API Reference

This page contains the full reference to pytest’s API.

Constants

pytest.__version__

The current pytest version, as a string:

>>> import pytest
>>> pytest.__version__
'7.0.0'

pytest.version_tuple

New in version 7.0.

The current pytest version, as a tuple:

>>> import pytest
>>> pytest.version_tuple
(7, 0, 0)

For pre-releases, the last component will be a string with the prerelease version:

>>> import pytest
>>> pytest.version_tuple
(7, 0, '0rc1')

Functions

pytest.approx

approx(expected, rel=None, abs=None, nan_ok=False)[source]

Assert that two numbers (or two ordered sequences of numbers) are equal to each other within some tolerance.

Due to the Floating Point Arithmetic: Issues and Limitations, numbers that we would intuitively expect to be equal are not always so:

>>> 0.1 + 0.2 == 0.3
False

This problem is commonly encountered when writing tests, e.g. when making sure that floating-point values are what you expect them to be. One way to deal with this problem is to assert that two floating-point numbers are equal to within some appropriate tolerance:

>>> abs((0.1 + 0.2) - 0.3) < 1e-6
True

However, comparisons like this are tedious to write and difficult to understand. Furthermore, absolute comparisons like the one above are usually discouraged because there’s no tolerance that works well for all situations. 1e-6 is good for numbers around 1, but too small for very big numbers and too big for very small ones. It’s better to express the tolerance as a fraction of the expected value, but relative comparisons like that are even more difficult to write correctly and concisely.

The approx class performs floating-point comparisons using a syntax that’s as intuitive as possible:

>>> from pytest import approx
>>> 0.1 + 0.2 == approx(0.3)
True

The same syntax also works for ordered sequences of numbers:

>>> (0.1 + 0.2, 0.2 + 0.4) == approx((0.3, 0.6))
True

numpy arrays:

>>> import numpy as np                                                          
>>> np.array([0.1, 0.2]) + np.array([0.2, 0.4]) == approx(np.array([0.3, 0.6])) 
True

And for a numpy array against a scalar:

>>> import numpy as np                                         
>>> np.array([0.1, 0.2]) + np.array([0.2, 0.1]) == approx(0.3) 
True

Only ordered sequences are supported, because approx needs to infer the relative position of the sequences without ambiguity. This means sets and other unordered sequences are not supported.

Finally, dictionary values can also be compared:

>>> {'a': 0.1 + 0.2, 'b': 0.2 + 0.4} == approx({'a': 0.3, 'b': 0.6})
True

The comparison will be true if both mappings have the same keys and their respective values match the expected tolerances.

Tolerances

By default, approx considers numbers within a relative tolerance of 1e-6 (i.e. one part in a million) of its expected value to be equal. This treatment would lead to surprising results if the expected value was 0.0, because nothing but 0.0 itself is relatively close to 0.0. To handle this case less surprisingly, approx also considers numbers within an absolute tolerance of 1e-12 of its expected value to be equal. Infinity and NaN are special cases. Infinity is only considered equal to itself, regardless of the relative tolerance. NaN is not considered equal to anything by default, but you can make it be equal to itself by setting the nan_ok argument to True. (This is meant to facilitate comparing arrays that use NaN to mean “no data”.)

Both the relative and absolute tolerances can be changed by passing arguments to the approx constructor:

>>> 1.0001 == approx(1)
False
>>> 1.0001 == approx(1, rel=1e-3)
True
>>> 1.0001 == approx(1, abs=1e-3)
True

If you specify abs but not rel, the comparison will not consider the relative tolerance at all. In other words, two numbers that are within the default relative tolerance of 1e-6 will still be considered unequal if they exceed the specified absolute tolerance. If you specify both abs and rel, the numbers will be considered equal if either tolerance is met:

>>> 1 + 1e-8 == approx(1)
True
>>> 1 + 1e-8 == approx(1, abs=1e-12)
False
>>> 1 + 1e-8 == approx(1, rel=1e-6, abs=1e-12)
True

You can also use approx to compare nonnumeric types, or dicts and sequences containing nonnumeric types, in which case it falls back to strict equality. This can be useful for comparing dicts and sequences that can contain optional values:

>>> {"required": 1.0000005, "optional": None} == approx({"required": 1, "optional": None})
True
>>> [None, 1.0000005] == approx([None,1])
True
>>> ["foo", 1.0000005] == approx([None,1])
False

If you’re thinking about using approx, then you might want to know how it compares to other good ways of comparing floating-point numbers. All of these algorithms are based on relative and absolute tolerances and should agree for the most part, but they do have meaningful differences:

  • math.isclose(a, b, rel_tol=1e-9, abs_tol=0.0): True if the relative tolerance is met w.r.t. either a or b or if the absolute tolerance is met. Because the relative tolerance is calculated w.r.t. both a and b, this test is symmetric (i.e. neither a nor b is a “reference value”). You have to specify an absolute tolerance if you want to compare to 0.0 because there is no tolerance by default. More information: math.isclose().

  • numpy.isclose(a, b, rtol=1e-5, atol=1e-8): True if the difference between a and b is less that the sum of the relative tolerance w.r.t. b and the absolute tolerance. Because the relative tolerance is only calculated w.r.t. b, this test is asymmetric and you can think of b as the reference value. Support for comparing sequences is provided by numpy.allclose(). More information: numpy.isclose.

  • unittest.TestCase.assertAlmostEqual(a, b): True if a and b are within an absolute tolerance of 1e-7. No relative tolerance is considered , so this function is not appropriate for very large or very small numbers. Also, it’s only available in subclasses of unittest.TestCase and it’s ugly because it doesn’t follow PEP8. More information: unittest.TestCase.assertAlmostEqual().

  • a == pytest.approx(b, rel=1e-6, abs=1e-12): True if the relative tolerance is met w.r.t. b or if the absolute tolerance is met. Because the relative tolerance is only calculated w.r.t. b, this test is asymmetric and you can think of b as the reference value. In the special case that you explicitly specify an absolute tolerance but not a relative tolerance, only the absolute tolerance is considered.

Note

approx can handle numpy arrays, but we recommend the specialised test helpers in Test Support (numpy.testing) if you need support for comparisons, NaNs, or ULP-based tolerances.

Warning

Changed in version 3.2.

In order to avoid inconsistent behavior, TypeError is raised for >, >=, < and <= comparisons. The example below illustrates the problem:

assert approx(0.1) > 0.1 + 1e-10  # calls approx(0.1).__gt__(0.1 + 1e-10)
assert 0.1 + 1e-10 > approx(0.1)  # calls approx(0.1).__lt__(0.1 + 1e-10)

In the second example one expects approx(0.1).__le__(0.1 + 1e-10) to be called. But instead, approx(0.1).__lt__(0.1 + 1e-10) is used to comparison. This is because the call hierarchy of rich comparisons follows a fixed behavior. More information: object.__ge__()

Changed in version 3.7.1: approx raises TypeError when it encounters a dict value or sequence element of nonnumeric type.

Changed in version 6.1.0: approx falls back to strict equality for nonnumeric types instead of raising TypeError.

Parameters

nan_ok (bool) –

Return type

_pytest.python_api.ApproxBase

pytest.fail

Tutorial: How to use skip and xfail to deal with tests that cannot succeed

fail(reason[, pytrace=True, msg=None])[source]

Explicitly fail an executing test with the given message.

Parameters
  • reason (str) – The message to show the user as reason for the failure.

  • pytrace (bool) – If False, msg represents the full failure information and no python traceback will be reported.

  • msg (Optional[str]) – Same as reason, but deprecated. Will be removed in a future version, use reason instead.

Return type

NoReturn

pytest.skip

skip(reason[, allow_module_level=False, msg=None])[source]

Skip an executing test with the given message.

This function should be called only during testing (setup, call or teardown) or during collection by using the allow_module_level flag. This function can be called in doctests as well.

Parameters
  • reason (str) – The message to show the user as reason for the skip.

  • allow_module_level (bool) – Allows this function to be called at module level, skipping the rest of the module. Defaults to False.

  • msg (Optional[str]) – Same as reason, but deprecated. Will be removed in a future version, use reason instead.

Return type

NoReturn

Note

It is better to use the pytest.mark.skipif marker when possible to declare a test to be skipped under certain conditions like mismatching platforms or dependencies. Similarly, use the # doctest: +SKIP directive (see doctest.SKIP) to skip a doctest statically.

pytest.importorskip

importorskip(modname, minversion=None, reason=None)[source]

Import and return the requested module modname, or skip the current test if the module cannot be imported.

Parameters
  • modname (str) – The name of the module to import.

  • minversion (str) – If given, the imported module’s __version__ attribute must be at least this minimal version, otherwise the test is still skipped.

  • reason (str) – If given, this reason is shown as the message when the module cannot be imported.

Returns

The imported module. This should be assigned to its canonical name.

Return type

Any

Example:

docutils = pytest.importorskip("docutils")

pytest.xfail

xfail(reason='')[source]

Imperatively xfail an executing test or setup function with the given reason.

This function should be called only during testing (setup, call or teardown).

Note

It is better to use the pytest.mark.xfail marker when possible to declare a test to be xfailed under certain conditions like known bugs or missing features.

Parameters

reason (str) –

Return type

NoReturn

pytest.exit

exit(reason[, returncode=False, msg=None])[source]

Exit testing process.

Parameters
  • reason (str) – The message to show as the reason for exiting pytest. reason has a default value only because msg is deprecated.

  • returncode (Optional[int]) – Return code to be used when exiting pytest.

  • msg (Optional[str]) – Same as reason, but deprecated. Will be removed in a future version, use reason instead.

Return type

NoReturn

pytest.main

main(args=None, plugins=None)[source]

Perform an in-process test run.

Parameters
  • args (Optional[Union[List[str], os.PathLike[str]]]) – List of command line arguments.

  • plugins (Optional[Sequence[Union[str, object]]]) – List of plugin objects to be auto-registered during initialization.

Returns

An exit code.

Return type

Union[int, _pytest.config.ExitCode]

pytest.param

param(*values[, id][, marks])[source]

Specify a parameter in pytest.mark.parametrize calls or parametrized fixtures.

@pytest.mark.parametrize(
    "test_input,expected",
    [
        ("3+5", 8),
        pytest.param("6*9", 42, marks=pytest.mark.xfail),
    ],
)
def test_eval(test_input, expected):
    assert eval(test_input) == expected
Parameters
  • values (object) – Variable args of the values of the parameter set, in order.

  • marks (Union[_pytest.mark.structures.MarkDecorator, Collection[Union[_pytest.mark.structures.MarkDecorator, _pytest.mark.structures.Mark]]]) – A single mark or a list of marks to be applied to this parameter set.

  • id (Optional[str]) – The id to attribute to this parameter set.

  • marks

  • id

Return type

_pytest.mark.structures.ParameterSet

pytest.raises

Tutorial: Assertions about expected exceptions

with raises(expected_exception: Exception[, *, match]) as excinfo[source]

Assert that a code block/function call raises expected_exception or raise a failure exception otherwise.

Parameters
  • match

    If specified, a string containing a regular expression, or a regular expression object, that is tested against the string representation of the exception using re.search(). To match a literal string that may contain special characters, the pattern can first be escaped with re.escape().

    (This is only used when pytest.raises() is used as a context manager, and passed through to the function otherwise. When using pytest.raises() as a function, you can use: pytest.raises(Exc, func, match="passed on").match("my pattern").)

  • expected_exception (Union[Type[E], Tuple[Type[E], ..]]) –

  • args (Any) –

  • kwargs (Any) –

Return type

Union[_pytest.python_api.RaisesContext[E], _pytest._code.code.ExceptionInfo[E]]

Use pytest.raises as a context manager, which will capture the exception of the given type:

>>> import pytest
>>> with pytest.raises(ZeroDivisionError):
...    1/0

If the code block does not raise the expected exception (ZeroDivisionError in the example above), or no exception at all, the check will fail instead.

You can also use the keyword argument match to assert that the exception matches a text or regex:

>>> with pytest.raises(ValueError, match='must be 0 or None'):
...     raise ValueError("value must be 0 or None")

>>> with pytest.raises(ValueError, match=r'must be \d+$'):
...     raise ValueError("value must be 42")

The context manager produces an ExceptionInfo object which can be used to inspect the details of the captured exception:

>>> with pytest.raises(ValueError) as exc_info:
...     raise ValueError("value must be 42")
>>> assert exc_info.type is ValueError
>>> assert exc_info.value.args[0] == "value must be 42"

Note

When using pytest.raises as a context manager, it’s worthwhile to note that normal context manager rules apply and that the exception raised must be the final line in the scope of the context manager. Lines of code after that, within the scope of the context manager will not be executed. For example:

>>> value = 15
>>> with pytest.raises(ValueError) as exc_info:
...     if value > 10:
...         raise ValueError("value must be <= 10")
...     assert exc_info.type is ValueError  # this will not execute

Instead, the following approach must be taken (note the difference in scope):

>>> with pytest.raises(ValueError) as exc_info:
...     if value > 10:
...         raise ValueError("value must be <= 10")
...
>>> assert exc_info.type is ValueError

Using with pytest.mark.parametrize

When using pytest.mark.parametrize it is possible to parametrize tests such that some runs raise an exception and others do not.

See Parametrizing conditional raising for an example.

Legacy form

It is possible to specify a callable by passing a to-be-called lambda:

>>> raises(ZeroDivisionError, lambda: 1/0)
<ExceptionInfo ...>

or you can specify an arbitrary callable with arguments:

>>> def f(x): return 1/x
...
>>> raises(ZeroDivisionError, f, 0)
<ExceptionInfo ...>
>>> raises(ZeroDivisionError, f, x=0)
<ExceptionInfo ...>

The form above is fully supported but discouraged for new code because the context manager form is regarded as more readable and less error-prone.

Note

Similar to caught exception objects in Python, explicitly clearing local references to returned ExceptionInfo objects can help the Python interpreter speed up its garbage collection.

Clearing those references breaks a reference cycle (ExceptionInfo –> caught exception –> frame stack raising the exception –> current frame stack –> local variables –> ExceptionInfo) which makes Python keep all objects referenced from that cycle (including all local variables in the current frame) alive until the next cyclic garbage collection run. More detailed information can be found in the official Python documentation for the try statement.

pytest.deprecated_call

Tutorial: Ensuring code triggers a deprecation warning

with deprecated_call()[source]

Assert that code produces a DeprecationWarning or PendingDeprecationWarning.

This function can be used as a context manager:

>>> import warnings
>>> def api_call_v2():
...     warnings.warn('use v3 of this api', DeprecationWarning)
...     return 200

>>> import pytest
>>> with pytest.deprecated_call():
...    assert api_call_v2() == 200

It can also be used by passing a function and *args and **kwargs, in which case it will ensure calling func(*args, **kwargs) produces one of the warnings types above. The return value is the return value of the function.

In the context manager form you may use the keyword argument match to assert that the warning matches a text or regex.

The context manager produces a list of warnings.WarningMessage objects, one for each warning raised.

Parameters
  • func (Optional[Callable[[..], Any]]) –

  • args (Any) –

  • kwargs (Any) –

Return type

Union[_pytest.recwarn.WarningsRecorder, Any]

pytest.register_assert_rewrite

Tutorial: Assertion Rewriting

register_assert_rewrite(*names)[source]

Register one or more module names to be rewritten on import.

This function will make sure that this module or all modules inside the package will get their assert statements rewritten. Thus you should make sure to call this before the module is actually imported, usually in your __init__.py if you are a plugin using a package.

Raises

TypeError – If the given module names are not strings.

Parameters

names (str) –

Return type

None

pytest.warns

Tutorial: Asserting warnings with the warns function

with warns(expected_warning: Exception[, match])[source]

Assert that code raises a particular class of warning.

Specifically, the parameter expected_warning can be a warning class or sequence of warning classes, and the inside the with block must issue a warning of that class or classes.

This helper produces a list of warnings.WarningMessage objects, one for each warning raised.

This function can be used as a context manager, or any of the other ways pytest.raises() can be used:

>>> import pytest
>>> with pytest.warns(RuntimeWarning):
...    warnings.warn("my warning", RuntimeWarning)

In the context manager form you may use the keyword argument match to assert that the warning matches a text or regex:

>>> with pytest.warns(UserWarning, match='must be 0 or None'):
...     warnings.warn("value must be 0 or None", UserWarning)

>>> with pytest.warns(UserWarning, match=r'must be \d+$'):
...     warnings.warn("value must be 42", UserWarning)

>>> with pytest.warns(UserWarning, match=r'must be \d+$'):
...     warnings.warn("this is not here", UserWarning)
Traceback (most recent call last):
  ...
Failed: DID NOT WARN. No warnings of type ...UserWarning... were emitted...
Parameters
  • expected_warning (Union[Type[Warning], Tuple[Type[Warning], ..]]) –

  • args (Any) –

  • match (Optional[Union[str, Pattern[str]]]) –

  • kwargs (Any) –

Return type

Union[_pytest.recwarn.WarningsChecker, Any]

pytest.freeze_includes

Tutorial: Freezing pytest

freeze_includes()[source]

Return a list of module names used by pytest that should be included by cx_freeze.

Return type

List[str]

Marks

Marks can be used apply meta data to test functions (but not fixtures), which can then be accessed by fixtures or plugins.

pytest.mark.filterwarnings

Tutorial: @pytest.mark.filterwarnings

Add warning filters to marked test items.

pytest.mark.filterwarnings(filter)
Parameters

filter (str) –

A warning specification string, which is composed of contents of the tuple (action, message, category, module, lineno) as specified in The Warnings Filter section of the Python documentation, separated by ":". Optional fields can be omitted. Module names passed for filtering are not regex-escaped.

For example:

@pytest.mark.filterwarnings("ignore:.*usage will be deprecated.*:DeprecationWarning")
def test_foo():
    ...

pytest.mark.skip

Tutorial: Skipping test functions

Unconditionally skip a test function.

pytest.mark.skip(reason=None)
Parameters

reason (str) – Reason why the test function is being skipped.

pytest.mark.skipif

Tutorial: Skipping test functions

Skip a test function if a condition is True.

pytest.mark.skipif(condition, *, reason=None)
Parameters
  • condition (bool or str) – True/False if the condition should be skipped or a condition string.

  • reason (str) – Reason why the test function is being skipped.

pytest.mark.usefixtures

Tutorial: Use fixtures in classes and modules with usefixtures

Mark a test function as using the given fixture names.

pytest.mark.usefixtures(*names)
Parameters

args – The names of the fixture to use, as strings.

Note

When using usefixtures in hooks, it can only load fixtures when applied to a test function before test setup (for example in the pytest_collection_modifyitems hook).

Also note that this mark has no effect when applied to fixtures.

pytest.mark.xfail

Tutorial: XFail: mark test functions as expected to fail

Marks a test function as expected to fail.

pytest.mark.xfail(condition=None, *, reason=None, raises=None, run=True, strict=False)
Parameters
  • condition (bool or str) – Condition for marking the test function as xfail (True/False or a condition string). If a bool, you also have to specify reason (see condition string).

  • reason (str) – Reason why the test function is marked as xfail.

  • raises (Type[Exception]) – Exception subclass (or tuple of subclasses) expected to be raised by the test function; other exceptions will fail the test.

  • run (bool) – If the test function should actually be executed. If False, the function will always xfail and will not be executed (useful if a function is segfaulting).

  • strict (bool) –

    • If False (the default) the function will be shown in the terminal output as xfailed if it fails and as xpass if it passes. In both cases this will not cause the test suite to fail as a whole. This is particularly useful to mark flaky tests (tests that fail at random) to be tackled later.

    • If True, the function will be shown in the terminal output as xfailed if it fails, but if it unexpectedly passes then it will fail the test suite. This is particularly useful to mark functions that are always failing and there should be a clear indication if they unexpectedly start to pass (for example a new release of a library fixes a known bug).

Custom marks

Marks are created dynamically using the factory object pytest.mark and applied as a decorator.

For example:

@pytest.mark.timeout(10, "slow", method="thread")
def test_function():
    ...

Will create and attach a Mark object to the collected Item, which can then be accessed by fixtures or hooks with Node.iter_markers. The mark object will have the following attributes:

mark.args == (10, "slow")
mark.kwargs == {"method": "thread"}

Example for using multiple custom markers:

@pytest.mark.timeout(10, "slow", method="thread")
@pytest.mark.slow
def test_function():
    ...

When Node.iter_markers or Node.iter_markers is used with multiple markers, the marker closest to the function will be iterated over first. The above example will result in @pytest.mark.slow followed by @pytest.mark.timeout(...).

Fixtures

Tutorial: Fixtures reference

Fixtures are requested by test functions or other fixtures by declaring them as argument names.

Example of a test requiring a fixture:

def test_output(capsys):
    print("hello")
    out, err = capsys.readouterr()
    assert out == "hello\n"

Example of a fixture requiring another fixture:

@pytest.fixture
def db_session(tmp_path):
    fn = tmp_path / "db.file"
    return connect(fn)

For more details, consult the full fixtures docs.

@pytest.fixture

@fixture(fixture_function=None, *, scope='function', params=None, autouse=False, ids=None, name=None)[source]

Decorator to mark a fixture factory function.

This decorator can be used, with or without parameters, to define a fixture function.

The name of the fixture function can later be referenced to cause its invocation ahead of running tests: test modules or classes can use the pytest.mark.usefixtures(fixturename) marker.

Test functions can directly use fixture names as input arguments in which case the fixture instance returned from the fixture function will be injected.

Fixtures can provide their values to test functions using return or yield statements. When using yield the code block after the yield statement is executed as teardown code regardless of the test outcome, and must yield exactly once.

Parameters
  • scope (Union[_ScopeName, Callable[[str, Config], _ScopeName]]) –

    The scope for which this fixture is shared; one of "function" (default), "class", "module", "package" or "session".

    This parameter may also be a callable which receives (fixture_name, config) as parameters, and must return a str with one of the values mentioned above.

    See Dynamic scope in the docs for more information.

  • params (Optional[Iterable[object]]) – An optional list of parameters which will cause multiple invocations of the fixture function and all of the tests using it. The current parameter is available in request.param.

  • autouse (bool) – If True, the fixture func is activated for all tests that can see it. If False (the default), an explicit reference is needed to activate the fixture.

  • ids (Optional[Union[Sequence[Optional[object]], Callable[[Any], Optional[object]]]]) – Sequence of ids each corresponding to the params so that they are part of the test id. If no ids are provided they will be generated automatically from the params.

  • name (Optional[str]) – The name of the fixture. This defaults to the name of the decorated function. If a fixture is used in the same module in which it is defined, the function name of the fixture will be shadowed by the function arg that requests the fixture; one way to resolve this is to name the decorated function fixture_<fixturename> and then use @pytest.fixture(name='<fixturename>').

  • fixture_function (Optional[FixtureFunction]) –

Return type

Union[_pytest.fixtures.FixtureFunctionMarker, FixtureFunction]

config.cache

Tutorial: How to re-run failed tests and maintain state between test runs

The config.cache object allows other plugins and fixtures to store and retrieve values across test runs. To access it from fixtures request pytestconfig into your fixture and get it with pytestconfig.cache.

Under the hood, the cache plugin uses the simple dumps/loads API of the json stdlib module.

config.cache is an instance of pytest.Cache:

final class Cache[source]
mkdir(name)[source]

Return a directory path object with the given name.

If the directory does not yet exist, it will be created. You can use it to manage files to e.g. store/retrieve database dumps across test sessions.

New in version 7.0.

Parameters

name (str) – Must be a string not containing a / separator. Make sure the name contains your plugin or application identifiers to prevent clashes with other cache users.

Return type

pathlib.Path

get(key, default)[source]

Return the cached value for the given key.

If no value was yet cached or the value cannot be read, the specified default is returned.

Parameters
  • key (str) – Must be a / separated value. Usually the first name is the name of your plugin or your application.

  • default – The value to return in case of a cache-miss or invalid cache value.

set(key, value)[source]

Save value for the given key.

Parameters
  • key (str) – Must be a / separated value. Usually the first name is the name of your plugin or your application.

  • value (object) – Must be of any combination of basic python types, including nested types like lists of dictionaries.

Return type

None

capsys

Tutorial: How to capture stdout/stderr output

capsys()[source]

Enable text capturing of writes to sys.stdout and sys.stderr.

The captured output is made available via capsys.readouterr() method calls, which return a (out, err) namedtuple. out and err will be text objects.

Returns an instance of CaptureFixture[str].

Example:

def test_output(capsys):
    print("hello")
    captured = capsys.readouterr()
    assert captured.out == "hello\n"
Parameters

request (_pytest.fixtures.SubRequest) –

Return type

Generator[_pytest.capture.CaptureFixture[str], None, None]

class CaptureFixture[source]

Object returned by the capsys, capsysbinary, capfd and capfdbinary fixtures.

readouterr()[source]

Read and return the captured output so far, resetting the internal buffer.

Returns

The captured content as a namedtuple with out and err string attributes.

Return type

_pytest.capture.CaptureResult

with disabled()[source]

Temporarily disable capturing while inside the with block.

Return type

Generator[None, None, None]

capsysbinary

Tutorial: How to capture stdout/stderr output

capsysbinary()[source]

Enable bytes capturing of writes to sys.stdout and sys.stderr.

The captured output is made available via capsysbinary.readouterr() method calls, which return a (out, err) namedtuple. out and err will be bytes objects.

Returns an instance of CaptureFixture[bytes].

Example:

def test_output(capsysbinary):
    print("hello")
    captured = capsysbinary.readouterr()
    assert captured.out == b"hello\n"
Parameters

request (_pytest.fixtures.SubRequest) –

Return type

Generator[_pytest.capture.CaptureFixture[bytes], None, None]

capfd

Tutorial: How to capture stdout/stderr output

capfd()[source]

Enable text capturing of writes to file descriptors 1 and 2.

The captured output is made available via capfd.readouterr() method calls, which return a (out, err) namedtuple. out and err will be text objects.

Returns an instance of CaptureFixture[str].

Example:

def test_system_echo(capfd):
    os.system('echo "hello"')
    captured = capfd.readouterr()
    assert captured.out == "hello\n"
Parameters

request (_pytest.fixtures.SubRequest) –

Return type

Generator[_pytest.capture.CaptureFixture[str], None, None]

capfdbinary

Tutorial: How to capture stdout/stderr output

capfdbinary()[source]

Enable bytes capturing of writes to file descriptors 1 and 2.

The captured output is made available via capfd.readouterr() method calls, which return a (out, err) namedtuple. out and err will be byte objects.

Returns an instance of CaptureFixture[bytes].

Example:

def test_system_echo(capfdbinary):
    os.system('echo "hello"')
    captured = capfdbinary.readouterr()
    assert captured.out == b"hello\n"
Parameters

request (_pytest.fixtures.SubRequest) –

Return type

Generator[_pytest.capture.CaptureFixture[bytes], None, None]

doctest_namespace

Tutorial: How to run doctests

doctest_namespace()[source]

Fixture that returns a dict that will be injected into the namespace of doctests.

Usually this fixture is used in conjunction with another autouse fixture:

@pytest.fixture(autouse=True)
def add_np(doctest_namespace):
    doctest_namespace["np"] = numpy

For more details: ‘doctest_namespace’ fixture.

Return type

Dict[str, Any]

request

Example: Pass different values to a test function, depending on command line options

The request fixture is a special fixture providing information of the requesting test function.

class FixtureRequest[source]

A request for a fixture from a test or fixture function.

A request object gives access to the requesting test context and has an optional param attribute in case the fixture is parametrized indirectly.

fixturename: Optional[str]

Fixture for which this request is being performed.

scope

Scope string, one of “function”, “class”, “module”, “package”, “session”.

fixturenames

Names of all active fixtures in this request.

node

Underlying collection node (depends on current request scope).

config

The pytest config object associated with this request.

function

Test function object if the request has a per-function scope.

cls

Class (can be None) where the test function was collected.

instance

Instance (can be None) on which test function was collected.

module

Python module object where the test function was collected.

path

Path where the test function was collected.

keywords

Keywords/markers dictionary for the underlying node.

session

Pytest session object.

addfinalizer(finalizer)[source]

Add finalizer/teardown function to be called after the last test within the requesting test context finished execution.

Parameters

finalizer (Callable[[], object]) –

Return type

None

applymarker(marker)[source]

Apply a marker to a single test function invocation.

This method is useful if you don’t want to have a keyword/marker on all function invocations.

Parameters

marker (Union[str, _pytest.mark.structures.MarkDecorator]) – A pytest.MarkDecorator object created by a call to pytest.mark.NAME(...).

Return type

None

raiseerror(msg)[source]

Raise a FixtureLookupError with the given message.

Parameters

msg (Optional[str]) –

Return type

NoReturn

getfixturevalue(argname)[source]

Dynamically run a named fixture function.

Declaring fixtures via function argument is recommended where possible. But if you can only decide whether to use another fixture at test setup time, you may use this function to retrieve it inside a fixture or test function body.

Raises

pytest.FixtureLookupError – If the given fixture could not be found.

Parameters

argname (str) –

Return type

Any

pytestconfig

pytestconfig()[source]

Session-scoped fixture that returns the session’s pytest.Config object.

Example:

def test_foo(pytestconfig):
    if pytestconfig.getoption("verbose") > 0:
        ...
Parameters

request (_pytest.fixtures.FixtureRequest) –

Return type

_pytest.config.Config

record_property

Tutorial: record_property

record_property()[source]

Add extra properties to the calling test.

User properties become part of the test report and are available to the configured reporters, like JUnit XML.

The fixture is callable with name, value. The value is automatically XML-encoded.

Example:

def test_function(record_property):
    record_property("example_key", 1)
Parameters

request (_pytest.fixtures.FixtureRequest) –

Return type

Callable[[str, object], None]

record_testsuite_property

Tutorial: record_testsuite_property

record_testsuite_property()[source]

Record a new <property> tag as child of the root <testsuite>.

This is suitable to writing global information regarding the entire test suite, and is compatible with xunit2 JUnit family.

This is a session-scoped fixture which is called with (name, value). Example:

def test_foo(record_testsuite_property):
    record_testsuite_property("ARCH", "PPC")
    record_testsuite_property("STORAGE_TYPE", "CEPH")

name must be a string, value will be converted to a string and properly xml-escaped.

Warning

Currently this fixture does not work with the pytest-xdist plugin. See issue #7767 for details.

Parameters

request (_pytest.fixtures.FixtureRequest) –

Return type

Callable[[str, object], None]

caplog

Tutorial: How to manage logging

caplog()[source]

Access and control log capturing.

Captured logs are available through the following properties/methods:

* caplog.messages        -> list of format-interpolated log messages
* caplog.text            -> string containing formatted log output
* caplog.records         -> list of logging.LogRecord instances
* caplog.record_tuples   -> list of (logger_name, level, message) tuples
* caplog.clear()         -> clear captured records and formatted log output string

Returns a pytest.LogCaptureFixture instance.

Parameters

request (_pytest.fixtures.FixtureRequest) –

Return type

Generator[_pytest.logging.LogCaptureFixture, None, None]

final class LogCaptureFixture[source]

Provides access and control of log capturing.

handler

Get the logging handler used by the fixture.

Return type

LogCaptureHandler

get_records(when)[source]

Get the logging records for one of the possible test phases.

Parameters

when (str) – Which test phase to obtain the records from. Valid values are: “setup”, “call” and “teardown”.

Returns

The list of captured records at the given stage.

Return type

List[logging.LogRecord]

New in version 3.4.

text

The formatted log text.

records

The list of log records.

record_tuples

A list of a stripped down version of log records intended for use in assertion comparison.

The format of the tuple is:

(logger_name, log_level, message)

messages

A list of format-interpolated log messages.

Unlike ‘records’, which contains the format string and parameters for interpolation, log messages in this list are all interpolated.

Unlike ‘text’, which contains the output from the handler, log messages in this list are unadorned with levels, timestamps, etc, making exact comparisons more reliable.

Note that traceback or stack info (from logging.exception() or the exc_info or stack_info arguments to the logging functions) is not included, as this is added by the formatter in the handler.

New in version 3.7.

clear()[source]

Reset the list of log records and the captured log text.

Return type

None

set_level(level, logger=None)[source]

Set the level of a logger for the duration of a test.

Changed in version 3.4: The levels of the loggers changed by this function will be restored to their initial values at the end of the test.

Parameters
  • level (int) – The level.

  • logger (str) – The logger to update. If not given, the root logger.

Return type

None

with at_level(level, logger=None)[source]

Context manager that sets the level for capturing of logs. After the end of the ‘with’ statement the level is restored to its original value.

Parameters
  • level (int) – The level.

  • logger (str) – The logger to update. If not given, the root logger.

Return type

Generator[None, None, None]

monkeypatch

Tutorial: How to monkeypatch/mock modules and environments

monkeypatch()[source]

A convenient fixture for monkey-patching.

The fixture provides these methods to modify objects, dictionaries, or os.environ:

All modifications will be undone after the requesting test function or fixture has finished. The raising parameter determines if a KeyError or AttributeError will be raised if the set/deletion operation does not have the specified target.

To undo modifications done by the fixture in a contained scope, use context().

Returns a MonkeyPatch instance.

Return type

Generator[_pytest.monkeypatch.MonkeyPatch, None, None]

final class MonkeyPatch[source]

Helper to conveniently monkeypatch attributes/items/environment variables/syspath.

Returned by the monkeypatch fixture.

Versionchanged:

6.2 Can now also be used directly as pytest.MonkeyPatch(), for when the fixture is not available. In this case, use with MonkeyPatch.context() as mp: or remember to call undo() explicitly.

classmethod with context()[source]

Context manager that returns a new MonkeyPatch object which undoes any patching done inside the with block upon exit.

Example:

import functools


def test_partial(monkeypatch):
    with monkeypatch.context() as m:
        m.setattr(functools, "partial", 3)

Useful in situations where it is desired to undo some patches before the test ends, such as mocking stdlib functions that might break pytest itself if mocked (for examples of this see issue #3290).

Return type

Generator[_pytest.monkeypatch.MonkeyPatch, None, None]

setattr(target, name, value=<notset>, raising=True)[source]

Set attribute value on target, memorizing the old value.

For example:

import os

monkeypatch.setattr(os, "getcwd", lambda: "/")

The code above replaces the os.getcwd() function by a lambda which always returns "/".

For convenience, you can specify a string as target which will be interpreted as a dotted import path, with the last part being the attribute name:

monkeypatch.setattr("os.getcwd", lambda: "/")

Raises AttributeError if the attribute does not exist, unless raising is set to False.

Where to patch

monkeypatch.setattr works by (temporarily) changing the object that a name points to with another one. There can be many names pointing to any individual object, so for patching to work you must ensure that you patch the name used by the system under test.

See the section Where to patch in the unittest.mock docs for a complete explanation, which is meant for unittest.mock.patch() but applies to monkeypatch.setattr as well.

Parameters
Return type

None

delattr(target, name=<notset>, raising=True)[source]

Delete attribute name from target.

If no name is specified and target is a string it will be interpreted as a dotted import path with the last part being the attribute name.

Raises AttributeError it the attribute does not exist, unless raising is set to False.

Parameters
  • target (Union[object, str]) –

  • name (Union[str, _pytest.monkeypatch.Notset]) –

  • raising (bool) –

Return type

None

setitem(dic, name, value)[source]

Set dictionary entry name to value.

Parameters
  • dic (MutableMapping[K, V]) –

  • name (K) –

  • value (V) –

Return type

None

delitem(dic, name, raising=True)[source]

Delete name from dict.

Raises KeyError if it doesn’t exist, unless raising is set to False.

Parameters
  • dic (MutableMapping[K, V]) –

  • name (K) –

  • raising (bool) –

Return type

None

setenv(name, value, prepend=None)[source]

Set environment variable name to value.

If prepend is a character, read the current environment variable value and prepend the value adjoined with the prepend character.

Parameters
  • name (str) –

  • value (str) –

  • prepend (Optional[str]) –

Return type

None

delenv(name, raising=True)[source]

Delete name from the environment.

Raises KeyError if it does not exist, unless raising is set to False.

Parameters
  • name (str) –

  • raising (bool) –

Return type

None

syspath_prepend(path)[source]

Prepend path to sys.path list of import locations.

Return type

None

chdir(path)[source]

Change the current working directory to the specified path.

Path can be a string or a path object.

Parameters

path (Union[str, os.PathLike[str]]) –

Return type

None

undo()[source]

Undo previous changes.

This call consumes the undo stack. Calling it a second time has no effect unless you do more monkeypatching after the undo call.

There is generally no need to call undo(), since it is called automatically during tear-down.

Note

The same monkeypatch fixture is used across a single test function invocation. If monkeypatch is used both by the test function itself and one of the test fixtures, calling undo() will undo all of the changes made in both functions.

Prefer to use context() instead.

Return type

None

pytester

New in version 6.2.

Provides a Pytester instance that can be used to run and test pytest itself.

It provides an empty directory where pytest can be executed in isolation, and contains facilities to write tests, configuration files, and match against expected output.

To use it, include in your topmost conftest.py file:

pytest_plugins = "pytester"
final class Pytester[source]

Facilities to write tests/configuration files, execute pytest in isolation, and match against expected output, perfect for black-box testing of pytest plugins.

It attempts to isolate the test run from external factors as much as possible, modifying the current working directory to path and environment variables during initialization.

Attributes:

Variables
  • path (Path) – temporary directory path used to create files/run tests from, etc.

  • plugins – A list of plugins to use with parseconfig() and runpytest(). Initially this is an empty list but plugins can be added to the list. The type of items to add to the list depends on the method using them so refer to them for details.

exception TimeoutExpired[source]
path

Temporary directory where files are created and pytest is executed.

make_hook_recorder(pluginmanager)[source]

Create a new HookRecorder for a PluginManager.

Parameters

pluginmanager (_pytest.config.PytestPluginManager) –

Return type

_pytest.pytester.HookRecorder

chdir()[source]

Cd into the temporary directory.

This is done automatically upon instantiation.

Return type

None

makefile(ext, *args, **kwargs)[source]

Create new text file(s) in the test directory.

Parameters
  • ext (str) – The extension the file(s) should use, including the dot, e.g. .py.

  • args (str) – All args are treated as strings and joined using newlines. The result is written as contents to the file. The name of the file is based on the test function requesting this fixture.

  • kwargs (str) – Each keyword is the name of a file, while the value of it will be written as contents of the file.

Return type

pathlib.Path

Examples:

pytester.makefile(".txt", "line1", "line2")

pytester.makefile(".ini", pytest="[pytest]\naddopts=-rs\n")

To create binary files, use pathlib.Path.write_bytes() directly:

filename = pytester.path.joinpath("foo.bin")
filename.write_bytes(b"...")
makeconftest(source)[source]

Write a contest.py file with ‘source’ as contents.

Parameters

source (str) –

Return type

pathlib.Path

makeini(source)[source]

Write a tox.ini file with ‘source’ as contents.

Parameters

source (str) –

Return type

pathlib.Path

getinicfg(source)[source]

Return the pytest section from the tox.ini config file.

Parameters

source (str) –

Return type

iniconfig.SectionWrapper

makepyprojecttoml(source)[source]

Write a pyproject.toml file with ‘source’ as contents.

New in version 6.0.

Parameters

source (str) –

Return type

pathlib.Path

makepyfile(*args, **kwargs)[source]

Shortcut for .makefile() with a .py extension.

Defaults to the test name with a ‘.py’ extension, e.g test_foobar.py, overwriting existing files.

Examples:

def test_something(pytester):
    # Initial file is created test_something.py.
    pytester.makepyfile("foobar")
    # To create multiple files, pass kwargs accordingly.
    pytester.makepyfile(custom="foobar")
    # At this point, both 'test_something.py' & 'custom.py' exist in the test directory.
Return type

pathlib.Path

maketxtfile(*args, **kwargs)[source]

Shortcut for .makefile() with a .txt extension.

Defaults to the test name with a ‘.txt’ extension, e.g test_foobar.txt, overwriting existing files.

Examples:

def test_something(pytester):
    # Initial file is created test_something.txt.
    pytester.maketxtfile("foobar")
    # To create multiple files, pass kwargs accordingly.
    pytester.maketxtfile(custom="foobar")
    # At this point, both 'test_something.txt' & 'custom.txt' exist in the test directory.
Return type

pathlib.Path

syspathinsert(path=None)[source]

Prepend a directory to sys.path, defaults to path.

This is undone automatically when this object dies at the end of each test.

Parameters

path (Optional[Union[str, os.PathLike[str]]]) –

Return type

None

mkdir(name)[source]

Create a new (sub)directory.

Parameters

name (str) –

Return type

pathlib.Path

mkpydir(name)[source]

Create a new python package.

This creates a (sub)directory with an empty __init__.py file so it gets recognised as a Python package.

Parameters

name (str) –

Return type

pathlib.Path

copy_example(name=None)[source]

Copy file from project’s directory into the testdir.

Parameters

name (str) – The name of the file to copy.

Returns

path to the copied directory (inside self.path).

Return type

pathlib.Path

getnode(config, arg)[source]

Return the collection node of a file.

Parameters
Return type

Optional[Union[_pytest.nodes.Item, _pytest.nodes.Collector]]

getpathnode(path)[source]

Return the collection node of a file.

This is like getnode() but uses parseconfigure() to create the (configured) pytest Config instance.

Parameters

path (os.PathLike[str]) – Path to the file.

genitems(colitems)[source]

Generate all test items from a collection node.

This recurses into the collection node and returns a list of all the test items contained within.

Parameters

colitems (Sequence[Union[_pytest.nodes.Item, _pytest.nodes.Collector]]) –

Return type

List[_pytest.nodes.Item]

runitem(source)[source]

Run the “test_func” Item.

The calling test instance (class containing the test method) must provide a .getrunner() method which should return a runner which can run the test protocol for a single item, e.g. _pytest.runner.runtestprotocol().

Parameters

source (str) –

Return type

Any

inline_runsource(source, *cmdlineargs)[source]

Run a test module in process using pytest.main().

This run writes “source” into a temporary file and runs pytest.main() on it, returning a HookRecorder instance for the result.

Parameters
  • source (str) – The source code of the test module.

  • cmdlineargs – Any extra command line arguments to use.

Return type

_pytest.pytester.HookRecorder

inline_genitems(*args)[source]

Run pytest.main(['--collectonly']) in-process.

Runs the pytest.main() function to run all of pytest inside the test process itself like inline_run(), but returns a tuple of the collected items and a HookRecorder instance.

Return type

Tuple[List[_pytest.nodes.Item], _pytest.pytester.HookRecorder]

inline_run(*args, plugins=(), no_reraise_ctrlc=False)[source]

Run pytest.main() in-process, returning a HookRecorder.

Runs the pytest.main() function to run all of pytest inside the test process itself. This means it can return a HookRecorder instance which gives more detailed results from that run than can be done by matching stdout/stderr from runpytest().

Parameters
  • args (Union[str, os.PathLike[str]]) – Command line arguments to pass to pytest.main().

  • plugins – Extra plugin instances the pytest.main() instance should use.

  • no_reraise_ctrlc (bool) – Typically we reraise keyboard interrupts from the child run. If True, the KeyboardInterrupt exception is captured.

Return type

_pytest.pytester.HookRecorder

runpytest_inprocess(*args, **kwargs)[source]

Return result of running pytest in-process, providing a similar interface to what self.runpytest() provides.

Parameters
Return type

_pytest.pytester.RunResult

runpytest(*args, **kwargs)[source]

Run pytest inline or in a subprocess, depending on the command line option “–runpytest” and return a RunResult.

Parameters
Return type

_pytest.pytester.RunResult

parseconfig(*args)[source]

Return a new pytest Config instance from given commandline args.

This invokes the pytest bootstrapping code in _pytest.config to create a new _pytest.core.PluginManager and call the pytest_cmdline_parse hook to create a new pytest.Config instance.

If plugins has been populated they should be plugin modules to be registered with the PluginManager.

Parameters

args (Union[str, os.PathLike[str]]) –

Return type

_pytest.config.Config

parseconfigure(*args)[source]

Return a new pytest configured Config instance.

Returns a new pytest.Config instance like parseconfig(), but also calls the pytest_configure hook.

Parameters

args (Union[str, os.PathLike[str]]) –

Return type

_pytest.config.Config

getitem(source, funcname='test_func')[source]

Return the test item for a test function.

Writes the source to a python file and runs pytest’s collection on the resulting module, returning the test item for the requested function name.

Parameters
  • source (Union[str, os.PathLike[str]]) – The module source.

  • funcname (str) – The name of the test function for which to return a test item.

Return type

_pytest.nodes.Item

getitems(source)[source]

Return all test items collected from the module.

Writes the source to a Python file and runs pytest’s collection on the resulting module, returning all test items contained within.

Parameters

source (Union[str, os.PathLike[str]]) –

Return type

List[_pytest.nodes.Item]

getmodulecol(source, configargs=(), *, withinit=False)[source]

Return the module collection node for source.

Writes source to a file using makepyfile() and then runs the pytest collection on it, returning the collection node for the test module.

Parameters
  • source (Union[str, os.PathLike[str]]) – The source code of the module to collect.

  • configargs – Any extra arguments to pass to parseconfigure().

  • withinit (bool) – Whether to also write an __init__.py file to the same directory to ensure it is a package.

collect_by_name(modcol, name)[source]

Return the collection node for name from the module collection.

Searches a module collection node for a collection node matching the given name.

Parameters
  • modcol (_pytest.nodes.Collector) – A module collection node; see getmodulecol().

  • name (str) – The name of the node to return.

Return type

Optional[Union[_pytest.nodes.Item, _pytest.nodes.Collector]]

popen(cmdargs, stdout=-1, stderr=-1, stdin=<NotSetType.token: 0>, **kw)[source]

Invoke subprocess.Popen.

Calls subprocess.Popen making sure the current working directory is in PYTHONPATH.

You probably want to use run() instead.

Parameters
  • cmdargs (Sequence[Union[str, os.PathLike[str]]]) –

  • stdout (Union[int, TextIO]) –

  • stderr (Union[int, TextIO]) –

  • stdin (Union[_pytest.compat.NotSetType, bytes, IO[Any], int]) –

run(*cmdargs, timeout=None, stdin=<NotSetType.token: 0>)[source]

Run a command with arguments.

Run a process using subprocess.Popen saving the stdout and stderr.

Parameters
  • cmdargs (Union[str, os.PathLike[str]]) – The sequence of arguments to pass to subprocess.Popen, with path-like objects being converted to str automatically.

  • timeout (Optional[float]) – The period in seconds after which to timeout and raise Pytester.TimeoutExpired.

  • stdin (Union[_pytest.compat.NotSetType, bytes, IO[Any], int]) –

    Optional standard input.

    • If it is CLOSE_STDIN (Default), then this method calls subprocess.Popen with stdin=subprocess.PIPE, and the standard input is closed immediately after the new command is started.

    • If it is of type bytes, these bytes are sent to the standard input of the command.

    • Otherwise, it is passed through to subprocess.Popen. For further information in this case, consult the document of the stdin parameter in subprocess.Popen.

Return type

_pytest.pytester.RunResult

runpython(script)[source]

Run a python script using sys.executable as interpreter.

Parameters

script (os.PathLike[str]) –

Return type

_pytest.pytester.RunResult

runpython_c(command)[source]

Run python -c "command".

Parameters

command (str) –

Return type

_pytest.pytester.RunResult

runpytest_subprocess(*args, timeout=None)[source]

Run pytest as a subprocess with given arguments.

Any plugins added to the plugins list will be added using the -p command line option. Additionally --basetemp is used to put any temporary files and directories in a numbered directory prefixed with “runpytest-” to not conflict with the normal numbered pytest location for temporary files and directories.

Parameters
Return type

_pytest.pytester.RunResult

spawn_pytest(string, expect_timeout=10.0)[source]

Run pytest using pexpect.

This makes sure to use the right pytest and sets up the temporary directory locations.

The pexpect child is returned.

Parameters
  • string (str) –

  • expect_timeout (float) –

Return type

pexpect.spawn

spawn(cmd, expect_timeout=10.0)[source]

Run a command using pexpect.

The pexpect child is returned.

Parameters
  • cmd (str) –

  • expect_timeout (float) –

Return type

pexpect.spawn

final class RunResult[source]

The result of running a command from Pytester.

ret: Union[int, _pytest.config.ExitCode]

The return value.

outlines

List of lines captured from stdout.

errlines

List of lines captured from stderr.

stdout

LineMatcher of stdout.

Use e.g. str(stdout) to reconstruct stdout, or the commonly used stdout.fnmatch_lines() method.

stderr

LineMatcher of stderr.

duration

Duration in seconds.

parseoutcomes()[source]

Return a dictionary of outcome noun -> count from parsing the terminal output that the test process produced.

The returned nouns will always be in plural form:

======= 1 failed, 1 passed, 1 warning, 1 error in 0.13s ====

Will return {"failed": 1, "passed": 1, "warnings": 1, "errors": 1}.

Return type

Dict[str, int]

classmethod parse_summary_nouns(lines)[source]

Extract the nouns from a pytest terminal summary line.

It always returns the plural noun for consistency:

======= 1 failed, 1 passed, 1 warning, 1 error in 0.13s ====

Will return {"failed": 1, "passed": 1, "warnings": 1, "errors": 1}.

Return type

Dict[str, int]

assert_outcomes(passed=0, skipped=0, failed=0, errors=0, xpassed=0, xfailed=0, warnings=None, deselected=None)[source]

Assert that the specified outcomes appear with the respective numbers (0 means it didn’t occur) in the text output from a test run.

warnings and deselected are only checked if not None.

Parameters
  • passed (int) –

  • skipped (int) –

  • failed (int) –

  • errors (int) –

  • xpassed (int) –

  • xfailed (int) –

  • warnings (Optional[int]) –

  • deselected (Optional[int]) –

Return type

None

class LineMatcher[source]

Flexible matching of text.

This is a convenience class to test large texts like the output of commands.

The constructor takes a list of lines without their trailing newlines, i.e. text.splitlines().

__str__()[source]

Return the entire original text.

New in version 6.2: You can use str() in older versions.

Return type

str

fnmatch_lines_random(lines2)[source]

Check lines exist in the output in any order (using fnmatch.fnmatch()).

Parameters

lines2 (Sequence[str]) –

Return type

None

re_match_lines_random(lines2)[source]

Check lines exist in the output in any order (using re.match()).

Parameters

lines2 (Sequence[str]) –

Return type

None

get_lines_after(fnline)[source]

Return all lines following the given line in the text.

The given line can contain glob wildcards.

Parameters

fnline (str) –

Return type

Sequence[str]

fnmatch_lines(lines2, *, consecutive=False)[source]

Check lines exist in the output (using fnmatch.fnmatch()).

The argument is a list of lines which have to match and can use glob wildcards. If they do not match a pytest.fail() is called. The matches and non-matches are also shown as part of the error message.

Parameters
  • lines2 (Sequence[str]) – String patterns to match.

  • consecutive (bool) – Match lines consecutively?

Return type

None

re_match_lines(lines2, *, consecutive=False)[source]

Check lines exist in the output (using re.match()).

The argument is a list of lines which have to match using re.match. If they do not match a pytest.fail() is called.

The matches and non-matches are also shown as part of the error message.

Parameters
  • lines2 (Sequence[str]) – string patterns to match.

  • consecutive (bool) – match lines consecutively?

Return type

None

no_fnmatch_line(pat)[source]

Ensure captured lines do not match the given pattern, using fnmatch.fnmatch.

Parameters

pat (str) – The pattern to match lines.

Return type

None

no_re_match_line(pat)[source]

Ensure captured lines do not match the given pattern, using re.match.

Parameters

pat (str) – The regular expression to match lines.

Return type

None

str()[source]

Return the entire original text.

Return type

str

final class HookRecorder[source]

Record all hooks called in a plugin manager.

Hook recorders are created by Pytester.

This wraps all the hook calls in the plugin manager, recording each call before propagating the normal calls.

getcalls(names)[source]

Get all recorded calls to hooks with the given names (or name).

Parameters

names (Union[str, Iterable[str]]) –

Return type

List[_pytest.pytester.RecordedHookCall]

matchreport(inamepart='', names=('pytest_runtest_logreport', 'pytest_collectreport'), when=None)[source]

Return a testreport whose dotted import path matches.

Parameters
  • inamepart (str) –

  • names (Union[str, Iterable[str]]) –

  • when (Optional[str]) –

Return type

Union[_pytest.reports.CollectReport, _pytest.reports.TestReport]

final class RecordedHookCall[source]

A recorded call to a hook.

The arguments to the hook call are set as attributes. For example:

calls = hook_recorder.getcalls("pytest_runtest_setup")
# Suppose pytest_runtest_setup was called once with `item=an_item`.
assert calls[0].item is an_item

testdir

Identical to pytester, but provides an instance whose methods return legacy py.path.local objects instead when applicable.

New code should avoid using testdir in favor of pytester.

final class Testdir[source]

Similar to Pytester, but this class works with legacy legacy_path objects instead.

All methods just forward to an internal Pytester instance, converting results to legacy_path objects as necessary.

exception TimeoutExpired
tmpdir

Temporary directory where tests are executed.

make_hook_recorder(pluginmanager)[source]

See Pytester.make_hook_recorder().

Return type

_pytest.pytester.HookRecorder

chdir()[source]

See Pytester.chdir().

Return type

None

finalize()[source]

See Pytester._finalize().

Return type

None

makefile(ext, *args, **kwargs)[source]

See Pytester.makefile().

Return type

py._path.local.LocalPath

makeconftest(source)[source]

See Pytester.makeconftest().

Return type

py._path.local.LocalPath

makeini(source)[source]

See Pytester.makeini().

Return type

py._path.local.LocalPath

getinicfg(source)[source]

See Pytester.getinicfg().

Parameters

source (str) –

Return type

iniconfig.SectionWrapper

makepyprojecttoml(source)[source]

See Pytester.makepyprojecttoml().

Return type

py._path.local.LocalPath

makepyfile(*args, **kwargs)[source]

See Pytester.makepyfile().

Return type

py._path.local.LocalPath

maketxtfile(*args, **kwargs)[source]

See Pytester.maketxtfile().

Return type

py._path.local.LocalPath

syspathinsert(path=None)[source]

See Pytester.syspathinsert().

Return type

None

mkdir(name)[source]

See Pytester.mkdir().

Return type

py._path.local.LocalPath

mkpydir(name)[source]

See Pytester.mkpydir().

Return type

py._path.local.LocalPath

copy_example(name=None)[source]

See Pytester.copy_example().

Return type

py._path.local.LocalPath

getnode(config, arg)[source]

See Pytester.getnode().

Parameters

config (_pytest.config.Config) –

Return type

Optional[Union[_pytest.nodes.Item, _pytest.nodes.Collector]]

getpathnode(path)[source]

See Pytester.getpathnode().

genitems(colitems)[source]

See Pytester.genitems().

Parameters

colitems (List[Union[_pytest.nodes.Item, _pytest.nodes.Collector]]) –

Return type

List[_pytest.nodes.Item]

runitem(source)[source]

See Pytester.runitem().

inline_runsource(source, *cmdlineargs)[source]

See Pytester.inline_runsource().

inline_genitems(*args)[source]

See Pytester.inline_genitems().

inline_run(*args, plugins=(), no_reraise_ctrlc=False)[source]

See Pytester.inline_run().

Parameters

no_reraise_ctrlc (bool) –

runpytest_inprocess(*args, **kwargs)[source]

See Pytester.runpytest_inprocess().

Return type

_pytest.pytester.RunResult

runpytest(*args, **kwargs)[source]

See Pytester.runpytest().

Return type

_pytest.pytester.RunResult

parseconfig(*args)[source]

See Pytester.parseconfig().

Return type

_pytest.config.Config

parseconfigure(*args)[source]

See Pytester.parseconfigure().

Return type

_pytest.config.Config

getitem(source, funcname='test_func')[source]

See Pytester.getitem().

getitems(source)[source]

See Pytester.getitems().

getmodulecol(source, configargs=(), withinit=False)[source]

See Pytester.getmodulecol().

collect_by_name(modcol, name)[source]

See Pytester.collect_by_name().

Parameters
  • modcol (_pytest.nodes.Collector) –

  • name (str) –

Return type

Optional[Union[_pytest.nodes.Item, _pytest.nodes.Collector]]

popen(cmdargs, stdout=-1, stderr=-1, stdin=<NotSetType.token: 0>, **kw)[source]

See Pytester.popen().

run(*cmdargs, timeout=None, stdin=<NotSetType.token: 0>)[source]

See Pytester.run().

Return type

_pytest.pytester.RunResult

runpython(script)[source]

See Pytester.runpython().

Return type

_pytest.pytester.RunResult

runpython_c(command)[source]

See Pytester.runpython_c().

runpytest_subprocess(*args, timeout=None)[source]

See Pytester.runpytest_subprocess().

Return type

_pytest.pytester.RunResult

spawn_pytest(string, expect_timeout=10.0)[source]

See Pytester.spawn_pytest().

Parameters
  • string (str) –

  • expect_timeout (float) –

Return type

pexpect.spawn

spawn(cmd, expect_timeout=10.0)[source]

See Pytester.spawn().

Parameters
  • cmd (str) –

  • expect_timeout (float) –

Return type

pexpect.spawn

recwarn

Tutorial: Asserting warnings with the warns function

recwarn()[source]

Return a WarningsRecorder instance that records all warnings emitted by test functions.

See https://docs.pytest.org/en/latest/how-to/capture-warnings.html for information on warning categories.

Return type

Generator[_pytest.recwarn.WarningsRecorder, None, None]

class WarningsRecorder[source]

A context manager to record raised warnings.

Each recorded warning is an instance of warnings.WarningMessage.

Adapted from warnings.catch_warnings.

Note

DeprecationWarning and PendingDeprecationWarning are treated differently; see Ensuring code triggers a deprecation warning.

list

The list of recorded warnings.

pop(cls=<class 'Warning'>)[source]

Pop the first recorded warning, raise exception if not exists.

Parameters

cls (Type[Warning]) –

Return type

warnings.WarningMessage

clear()[source]

Clear the list of recorded warnings.

Return type

None

tmp_path

Tutorial: How to use temporary directories and files in tests

tmp_path()[source]

Return a temporary directory path object which is unique to each test function invocation, created as a sub directory of the base temporary directory.

By default, a new base temporary directory is created each test session, and old bases are removed after 3 sessions, to aid in debugging. If --basetemp is used then it is cleared each session. See The default base temporary directory.

The returned object is a pathlib.Path object.

Parameters
  • request (_pytest.fixtures.FixtureRequest) –

  • tmp_path_factory (_pytest.tmpdir.TempPathFactory) –

Return type

pathlib.Path

tmp_path_factory

Tutorial: The tmp_path_factory fixture

tmp_path_factory is an instance of TempPathFactory:

final class TempPathFactory[source]

Factory for temporary directories under the common base temp directory.

The base directory can be configured using the --basetemp option.

mktemp(basename, numbered=True)[source]

Create a new temporary directory managed by the factory.

Parameters
  • basename (str) – Directory base name, must be a relative path.

  • numbered (bool) – If True, ensure the directory is unique by adding a numbered suffix greater than any existing one: basename="foo-" and numbered=True means that this function will create directories named "foo-0", "foo-1", "foo-2" and so on.

Returns

The path to the new directory.

Return type

pathlib.Path

getbasetemp()[source]

Return the base temporary directory, creating it if needed.

Return type

pathlib.Path

tmpdir

Tutorial: The tmpdir and tmpdir_factory fixtures

tmpdir()

Return a temporary directory path object which is unique to each test function invocation, created as a sub directory of the base temporary directory.

By default, a new base temporary directory is created each test session, and old bases are removed after 3 sessions, to aid in debugging. If --basetemp is used then it is cleared each session. See The default base temporary directory.

The returned object is a legacy_path object.

Note

These days, it is preferred to use tmp_path.

About the tmpdir and tmpdir_factory fixtures.

Parameters

tmp_path (pathlib.Path) –

Return type

py._path.local.LocalPath

tmpdir_factory

Tutorial: The tmpdir and tmpdir_factory fixtures

tmpdir_factory is an instance of TempdirFactory:

final class TempdirFactory[source]

Backward compatibility wrapper that implements py.path.local for TempPathFactory.

Note

These days, it is preferred to use tmp_path_factory.

About the tmpdir and tmpdir_factory fixtures.

mktemp(basename, numbered=True)[source]

Same as TempPathFactory.mktemp(), but returns a py.path.local object.

Parameters
  • basename (str) –

  • numbered (bool) –

Return type

py._path.local.LocalPath

getbasetemp()[source]

Same as TempPathFactory.getbasetemp(), but returns a py.path.local object.

Return type

py._path.local.LocalPath

Hooks

Tutorial: Writing plugins

Reference to all hooks which can be implemented by conftest.py files and plugins.

Bootstrapping hooks

Bootstrapping hooks called for plugins registered early enough (internal and setuptools plugins).

pytest_load_initial_conftests(early_config, parser, args)[source]

Called to implement the loading of initial conftest files ahead of command line option parsing.

Note

This hook will not be called for conftest.py files, only for setuptools plugins.

Parameters
  • early_config (pytest.Config) – The pytest config object.

  • args (List[str]) – Arguments passed on the command line.

  • parser (pytest.Parser) – To add command line options.

Return type

None

pytest_cmdline_preparse(config, args)[source]

(Deprecated) modify command line arguments before option parsing.

This hook is considered deprecated and will be removed in a future pytest version. Consider using pytest_load_initial_conftests instead.

Note

This hook will not be called for conftest.py files, only for setuptools plugins.

Parameters
  • config (pytest.Config) – The pytest config object.

  • args (List[str]) – Arguments passed on the command line.

Return type

None

pytest_cmdline_parse(pluginmanager, args)[source]

Return an initialized config object, parsing the specified args.

Stops at first non-None result, see firstresult: stop at first non-None result.

Note

This hook will only be called for plugin classes passed to the plugins arg when using pytest.main to perform an in-process test run.

Parameters
Return type

Optional[Config]

pytest_cmdline_main(config)[source]

Called for performing the main command line action. The default implementation will invoke the configure hooks and runtest_mainloop.

Stops at first non-None result, see firstresult: stop at first non-None result.

Parameters

config (pytest.Config) – The pytest config object.

Return type

Optional[Union[ExitCode, int]]

Initialization hooks

Initialization hooks called for plugins and conftest.py files.

pytest_addoption(parser, pluginmanager)[source]

Register argparse-style options and ini-style config values, called once at the beginning of a test run.

Note

This function should be implemented only in plugins or conftest.py files situated at the tests root directory due to how pytest discovers plugins during startup.

Parameters
Return type

None

Options can later be accessed through the config object, respectively:

The config object is passed around on many internal objects via the .config attribute or can be retrieved as the pytestconfig fixture.

Note

This hook is incompatible with hookwrapper=True.

pytest_addhooks(pluginmanager)[source]

Called at plugin registration time to allow adding new hooks via a call to pluginmanager.add_hookspecs(module_or_class, prefix).

Parameters

pluginmanager (pytest.PytestPluginManager) – The pytest plugin manager.

Return type

None

Note

This hook is incompatible with hookwrapper=True.

pytest_configure(config)[source]

Allow plugins and conftest files to perform initial configuration.

This hook is called for every plugin and initial conftest file after command line options have been parsed.

After that, the hook is called for other conftest files as they are imported.

Note

This hook is incompatible with hookwrapper=True.

Parameters

config (pytest.Config) – The pytest config object.

Return type

None

pytest_unconfigure(config)[source]

Called before test process is exited.

Parameters

config (pytest.Config) – The pytest config object.

Return type

None

pytest_sessionstart(session)[source]

Called after the Session object has been created and before performing collection and entering the run test loop.

Parameters

session (pytest.Session) – The pytest session object.

Return type

None

pytest_sessionfinish(session, exitstatus)[source]

Called after whole test run finished, right before returning the exit status to the system.

Parameters
  • session (pytest.Session) – The pytest session object.

  • exitstatus (int) – The status which pytest will return to the system.

Return type

None

pytest_plugin_registered(plugin, manager)[source]

A new pytest plugin got registered.

Parameters
Return type

None

Note

This hook is incompatible with hookwrapper=True.

Collection hooks

pytest calls the following hooks for collecting files and directories:

pytest_collection(session)[source]

Perform the collection phase for the given session.

Stops at first non-None result, see firstresult: stop at first non-None result. The return value is not used, but only stops further processing.

The default collection phase is this (see individual hooks for full details):

  1. Starting from session as the initial collector:

  1. pytest_collectstart(collector)

  2. report = pytest_make_collect_report(collector)

  3. pytest_exception_interact(collector, call, report) if an interactive exception occurred

  4. For each collected node:

  1. If an item, pytest_itemcollected(item)

  2. If a collector, recurse into it.

  1. pytest_collectreport(report)

  1. pytest_collection_modifyitems(session, config, items)

  1. pytest_deselected(items) for any deselected items (may be called multiple times)

  1. pytest_collection_finish(session)

  2. Set session.items to the list of collected items

  3. Set session.testscollected to the number of collected items

You can implement this hook to only perform some action before collection, for example the terminal plugin uses it to start displaying the collection counter (and returns None).

Parameters

session (pytest.Session) – The pytest session object.

Return type

Optional[object]

pytest_ignore_collect(collection_path, path, config)[source]

Return True to prevent considering this path for collection.

This hook is consulted for all files and directories prior to calling more specific hooks.

Stops at first non-None result, see firstresult: stop at first non-None result.

:param pathlib.Path collection_path : The path to analyze. :param LEGACY_PATH path: The path to analyze (deprecated). :param pytest.Config config: The pytest config object.

Changed in version 7.0.0: The collection_path parameter was added as a pathlib.Path equivalent of the path parameter. The path parameter has been deprecated.

Parameters
Return type

Optional[bool]

pytest_collect_file(file_path, path, parent)[source]

Create a Collector for the given path, or None if not relevant.

The new node needs to have the specified parent as a parent.

Parameters
  • file_path (pathlib.Path) – The path to analyze.

  • path (LEGACY_PATH) – The path to collect (deprecated).

  • parent (Collector) –

Return type

Optional[Collector]

Changed in version 7.0.0: The file_path parameter was added as a pathlib.Path equivalent of the path parameter. The path parameter has been deprecated.

pytest_pycollect_makemodule(module_path, path, parent)[source]

Return a Module collector or None for the given path.

This hook will be called for each matching test module path. The pytest_collect_file hook needs to be used if you want to create test modules for files that do not match as a test module.

Stops at first non-None result, see firstresult: stop at first non-None result.

Parameters
  • module_path (pathlib.Path) – The path of the module to collect.

  • path (LEGACY_PATH) – The path of the module to collect (deprecated).

Return type

Optional[Module]

Changed in version 7.0.0: The module_path parameter was added as a pathlib.Path equivalent of the path parameter.

The path parameter has been deprecated in favor of fspath.

For influencing the collection of objects in Python modules you can use the following hook:

pytest_pycollect_makeitem(collector, name, obj)[source]

Return a custom item/collector for a Python object in a module, or None.

Stops at first non-None result, see firstresult: stop at first non-None result.

Parameters
Return type

Union[None, Item, Collector, List[Union[Item, Collector]]]

pytest_generate_tests(metafunc)[source]

Generate (multiple) parametrized calls to a test function.

Parameters

metafunc (Metafunc) –

Return type

None

pytest_make_parametrize_id(config, val, argname)[source]

Return a user-friendly string representation of the given val that will be used by @pytest.mark.parametrize calls, or None if the hook doesn’t know about val.

The parameter name is available as argname, if required.

Stops at first non-None result, see firstresult: stop at first non-None result.

Parameters
  • config (pytest.Config) – The pytest config object.

  • val (object) – The parametrized value.

  • argname (str) – The automatic parameter name produced by pytest.

Return type

Optional[str]

Hooks for influencing test skipping:

pytest_markeval_namespace(config)[source]

Called when constructing the globals dictionary used for evaluating string conditions in xfail/skipif markers.

This is useful when the condition for a marker requires objects that are expensive or impossible to obtain during collection time, which is required by normal boolean conditions.

New in version 6.2.

Parameters

config (pytest.Config) – The pytest config object.

Returns

A dictionary of additional globals to add.

Return type

Dict[str, Any]

After collection is complete, you can modify the order of items, delete or otherwise amend the test items:

pytest_collection_modifyitems(session, config, items)[source]

Called after collection has been performed. May filter or re-order the items in-place.

Parameters
Return type

None

Note

If this hook is implemented in conftest.py files, it always receives all collected items, not only those under the conftest.py where it is implemented.

pytest_collection_finish(session)[source]

Called after collection has been performed and modified.

Parameters

session (pytest.Session) – The pytest session object.

Return type

None

Test running (runtest) hooks

All runtest related hooks receive a pytest.Item object.

pytest_runtestloop(session)[source]

Perform the main runtest loop (after collection finished).

The default hook implementation performs the runtest protocol for all items collected in the session (session.items), unless the collection failed or the collectonly pytest option is set.

If at any point pytest.exit() is called, the loop is terminated immediately.

If at any point session.shouldfail or session.shouldstop are set, the loop is terminated after the runtest protocol for the current item is finished.

Parameters

session (pytest.Session) – The pytest session object.

Return type

Optional[object]

Stops at first non-None result, see firstresult: stop at first non-None result. The return value is not used, but only stops further processing.

pytest_runtest_protocol(item, nextitem)[source]

Perform the runtest protocol for a single test item.

The default runtest protocol is this (see individual hooks for full details):

  • pytest_runtest_logstart(nodeid, location)

  • Setup phase:
    • call = pytest_runtest_setup(item) (wrapped in CallInfo(when="setup"))

    • report = pytest_runtest_makereport(item, call)

    • pytest_runtest_logreport(report)

    • pytest_exception_interact(call, report) if an interactive exception occurred

  • Call phase, if the the setup passed and the setuponly pytest option is not set:
    • call = pytest_runtest_call(item) (wrapped in CallInfo(when="call"))

    • report = pytest_runtest_makereport(item, call)

    • pytest_runtest_logreport(report)

    • pytest_exception_interact(call, report) if an interactive exception occurred

  • Teardown phase:
    • call = pytest_runtest_teardown(item, nextitem) (wrapped in CallInfo(when="teardown"))

    • report = pytest_runtest_makereport(item, call)

    • pytest_runtest_logreport(report)

    • pytest_exception_interact(call, report) if an interactive exception occurred

  • pytest_runtest_logfinish(nodeid, location)

Parameters
  • item (Item) – Test item for which the runtest protocol is performed.

  • nextitem (Optional[Item]) – The scheduled-to-be-next test item (or None if this is the end my friend).

Return type

Optional[object]

Stops at first non-None result, see firstresult: stop at first non-None result. The return value is not used, but only stops further processing.

pytest_runtest_logstart(nodeid, location)[source]

Called at the start of running the runtest protocol for a single item.

See pytest_runtest_protocol for a description of the runtest protocol.

Parameters
  • nodeid (str) – Full node ID of the item.

  • location (Tuple[str, Optional[int], str]) – A tuple of (filename, lineno, testname).

Return type

None

pytest_runtest_logfinish(nodeid, location)[source]

Called at the end of running the runtest protocol for a single item.

See pytest_runtest_protocol for a description of the runtest protocol.

Parameters
  • nodeid (str) – Full node ID of the item.

  • location (Tuple[str, Optional[int], str]) – A tuple of (filename, lineno, testname).

Return type

None

pytest_runtest_setup(item)[source]

Called to perform the setup phase for a test item.

The default implementation runs setup() on item and all of its parents (which haven’t been setup yet). This includes obtaining the values of fixtures required by the item (which haven’t been obtained yet).

Parameters

item (Item) –

Return type

None

pytest_runtest_call(item)[source]

Called to run the test for test item (the call phase).

The default implementation calls item.runtest().

Parameters

item (Item) –

Return type

None

pytest_runtest_teardown(item, nextitem)[source]

Called to perform the teardown phase for a test item.

The default implementation runs the finalizers and calls teardown() on item and all of its parents (which need to be torn down). This includes running the teardown phase of fixtures required by the item (if they go out of scope).

Parameters
  • nextitem (Optional[Item]) – The scheduled-to-be-next test item (None if no further test item is scheduled). This argument is used to perform exact teardowns, i.e. calling just enough finalizers so that nextitem only needs to call setup functions.

  • item (Item) –

Return type

None

pytest_runtest_makereport(item, call)[source]

Called to create a TestReport for each of the setup, call and teardown runtest phases of a test item.

See pytest_runtest_protocol for a description of the runtest protocol.

Parameters
Return type

Optional[TestReport]

Stops at first non-None result, see firstresult: stop at first non-None result.

For deeper understanding you may look at the default implementation of these hooks in _pytest.runner and maybe also in _pytest.pdb which interacts with _pytest.capture and its input/output capturing in order to immediately drop into interactive debugging when a test failure occurs.

pytest_pyfunc_call(pyfuncitem)[source]

Call underlying test function.

Stops at first non-None result, see firstresult: stop at first non-None result.

Parameters

pyfuncitem (Function) –

Return type

Optional[object]

Reporting hooks

Session related reporting hooks:

pytest_collectstart(collector)[source]

Collector starts collecting.

Parameters

collector (Collector) –

Return type

None

pytest_make_collect_report(collector)[source]

Perform collector.collect() and return a CollectReport.

Stops at first non-None result, see firstresult: stop at first non-None result.

Parameters

collector (Collector) –

Return type

Optional[CollectReport]

pytest_itemcollected(item)[source]

We just collected a test item.

Parameters

item (Item) –

Return type

None

pytest_collectreport(report)[source]

Collector finished collecting.

Parameters

report (CollectReport) –

Return type

None

pytest_deselected(items)[source]

Called for deselected test items, e.g. by keyword.

May be called multiple times.

Parameters

items (Sequence[Item]) –

Return type

None

pytest_report_header(config, start_path, startdir)[source]

Return a string or list of strings to be displayed as header info for terminal reporting.

Parameters
  • config (pytest.Config) – The pytest config object.

  • start_path (Path) – The starting dir.

  • startdir (LEGACY_PATH) – The starting dir (deprecated).

Return type

Union[str, List[str]]

Note

Lines returned by a plugin are displayed before those of plugins which ran before it. If you want to have your line(s) displayed first, use trylast=True.

Note

This function should be implemented only in plugins or conftest.py files situated at the tests root directory due to how pytest discovers plugins during startup.

Changed in version 7.0.0: The start_path parameter was added as a pathlib.Path equivalent of the startdir parameter. The startdir parameter has been deprecated.

pytest_report_collectionfinish(config, start_path, startdir, items)[source]

Return a string or list of strings to be displayed after collection has finished successfully.

These strings will be displayed after the standard “collected X items” message.

New in version 3.2.

Parameters
  • config (pytest.Config) – The pytest config object.

  • start_path (Path) – The starting dir.

  • startdir (LEGACY_PATH) – The starting dir (deprecated).

  • items (Sequence[Item]) – List of pytest items that are going to be executed; this list should not be modified.

Return type

Union[str, List[str]]

Note

Lines returned by a plugin are displayed before those of plugins which ran before it. If you want to have your line(s) displayed first, use trylast=True.

Changed in version 7.0.0: The start_path parameter was added as a pathlib.Path equivalent of the startdir parameter. The startdir parameter has been deprecated.

pytest_report_teststatus(report, config)[source]

Return result-category, shortletter and verbose word for status reporting.

The result-category is a category in which to count the result, for example “passed”, “skipped”, “error” or the empty string.

The shortletter is shown as testing progresses, for example “.”, “s”, “E” or the empty string.

The verbose word is shown as testing progresses in verbose mode, for example “PASSED”, “SKIPPED”, “ERROR” or the empty string.

pytest may style these implicitly according to the report outcome. To provide explicit styling, return a tuple for the verbose word, for example "rerun", "R", ("RERUN", {"yellow": True}).

Parameters
Return type

Tuple[str, str, Union[str, Mapping[str, bool]]]

Stops at first non-None result, see firstresult: stop at first non-None result.

pytest_report_to_serializable(config, report)[source]

Serialize the given report object into a data structure suitable for sending over the wire, e.g. converted to JSON.

Parameters
Return type

Optional[Dict[str, Any]]

pytest_report_from_serializable(config, data)[source]

Restore a report object previously serialized with pytest_report_to_serializable.

Parameters
  • config (Config) –

  • data (Dict[str, Any]) –

Return type

Optional[Union[CollectReport, TestReport]]

pytest_terminal_summary(terminalreporter, exitstatus, config)[source]

Add a section to terminal summary reporting.

Parameters
  • terminalreporter (_pytest.terminal.TerminalReporter) – The internal terminal reporter object.

  • exitstatus (int) – The exit status that will be reported back to the OS.

  • config (pytest.Config) – The pytest config object.

Return type

None

New in version 4.2: The config parameter.

pytest_fixture_setup(fixturedef, request)[source]

Perform fixture setup execution.

Returns

The return value of the call to the fixture function.

Parameters
  • fixturedef (FixtureDef[Any]) –

  • request (SubRequest) –

Return type

Optional[object]

Stops at first non-None result, see firstresult: stop at first non-None result.

Note

If the fixture function returns None, other implementations of this hook function will continue to be called, according to the behavior of the firstresult: stop at first non-None result option.

pytest_fixture_post_finalizer(fixturedef, request)[source]

Called after fixture teardown, but before the cache is cleared, so the fixture result fixturedef.cached_result is still available (not None).

Parameters
  • fixturedef (FixtureDef[Any]) –

  • request (SubRequest) –

Return type

None

pytest_warning_recorded(warning_message, when, nodeid, location)[source]

Process a warning captured by the internal pytest warnings plugin.

Parameters
  • warning_message (warnings.WarningMessage) – The captured warning. This is the same object produced by warnings.catch_warnings(), and contains the same attributes as the parameters of warnings.showwarning().

  • when (str) –

    Indicates when the warning was captured. Possible values:

    • "config": during pytest configuration/initialization stage.

    • "collect": during test collection.

    • "runtest": during test execution.

  • nodeid (str) – Full id of the item.

  • location (tuple|None) – When available, holds information about the execution context of the captured warning (filename, linenumber, function). function evaluates to <module> when the execution context is at the module level.

Return type

None

New in version 6.0.

Central hook for reporting about test execution:

pytest_runtest_logreport(report)[source]

Process the TestReport produced for each of the setup, call and teardown runtest phases of an item.

See pytest_runtest_protocol for a description of the runtest protocol.

Parameters

report (TestReport) –

Return type

None

Assertion related hooks:

pytest_assertrepr_compare(config, op, left, right)[source]

Return explanation for comparisons in failing assert expressions.

Return None for no custom explanation, otherwise return a list of strings. The strings will be joined by newlines but any newlines in a string will be escaped. Note that all but the first line will be indented slightly, the intention is for the first line to be a summary.

Parameters
Return type

Optional[List[str]]

pytest_assertion_pass(item, lineno, orig, expl)[source]

Called whenever an assertion passes.

New in version 5.0.

Use this hook to do some processing after a passing assertion. The original assertion information is available in the orig string and the pytest introspected assertion information is available in the expl string.

This hook must be explicitly enabled by the enable_assertion_pass_hook ini-file option:

[pytest]
enable_assertion_pass_hook=true

You need to clean the .pyc files in your project directory and interpreter libraries when enabling this option, as assertions will require to be re-written.

Parameters
  • item (pytest.Item) – pytest item object of current test.

  • lineno (int) – Line number of the assert statement.

  • orig (str) – String with the original assertion.

  • expl (str) – String with the assert explanation.

Return type

None

Debugging/Interaction hooks

There are few hooks which can be used for special reporting or interaction with exceptions:

pytest_internalerror(excrepr, excinfo)[source]

Called for internal errors.

Return True to suppress the fallback handling of printing an INTERNALERROR message directly to sys.stderr.

Parameters
Return type

Optional[bool]

pytest_keyboard_interrupt(excinfo)[source]

Called for keyboard interrupt.

Parameters

excinfo (ExceptionInfo[Union[KeyboardInterrupt, Exit]]) –

Return type

None

pytest_exception_interact(node, call, report)[source]

Called when an exception was raised which can potentially be interactively handled.

May be called during collection (see pytest_make_collect_report), in which case report is a CollectReport.

May be called during runtest of an item (see pytest_runtest_protocol), in which case report is a TestReport.

This hook is not called if the exception that was raised is an internal exception like skip.Exception.

Parameters
Return type

None

pytest_enter_pdb(config, pdb)[source]

Called upon pdb.set_trace().

Can be used by plugins to take special action just before the python debugger enters interactive mode.

Parameters
Return type

None

pytest_leave_pdb(config, pdb)[source]

Called when leaving pdb (e.g. with continue after pdb.set_trace()).

Can be used by plugins to take special action just after the python debugger leaves interactive mode.

Parameters
Return type

None

Objects

Full reference to objects accessible from fixtures or hooks.

CallInfo

final class CallInfo[source]

Result/Exception info of a function invocation.

excinfo: Optional[_pytest._code.code.ExceptionInfo[BaseException]]

The captured exception of the call, if it raised.

start: float

The system time when the call started, in seconds since the epoch.

stop: float

The system time when the call ended, in seconds since the epoch.

duration: float

The call duration, in seconds.

when: Literal[collect, setup, call, teardown]

The context of invocation: “collect”, “setup”, “call” or “teardown”.

result

The return value of the call, if it didn’t raise.

Can only be accessed if excinfo is None.

classmethod from_call(func, when, reraise=None)[source]

Call func, wrapping the result in a CallInfo.

Parameters
  • func (Callable[[], TResult]) – The function to call. Called without arguments.

  • when (Literal['collect', 'setup', 'call', 'teardown']) – The phase in which the function is called.

  • reraise (Optional[Union[Type[BaseException], Tuple[Type[BaseException], ..]]]) – Exception or exceptions that shall propagate if raised by the function, instead of being wrapped in the CallInfo.

Return type

CallInfo[TResult]

Class

class Class[source]

Bases: _pytest.python.PyCollector

Collector for test methods.

classmethod from_parent(parent, *, name, obj=None, **kw)[source]

The public constructor.

collect()[source]

Return a list of children (items and collectors) for this collection node.

Return type

Iterable[Union[_pytest.nodes.Item, _pytest.nodes.Collector]]

Collector

class Collector[source]

Bases: _pytest.nodes.Node

Collector instances create children through collect() and thus iteratively build a tree.

exception CollectError[source]

Bases: Exception

An error during collection, contains a custom message.

collect()[source]

Return a list of children (items and collectors) for this collection node.

Return type

Iterable[Union[_pytest.nodes.Item, _pytest.nodes.Collector]]

repr_failure(excinfo)[source]

Return a representation of a collection failure.

Parameters

excinfo (_pytest._code.code.ExceptionInfo[BaseException]) – Exception information for the failure.

Return type

Union[str, _pytest._code.code.TerminalRepr]

CollectReport

final class CollectReport[source]

Bases: _pytest.reports.BaseReport

Collection report object.

Reports can contain arbitrary extra attributes.

nodeid: str

Normalized collection nodeid.

outcome: Literal[passed, failed, skipped]

Test outcome, always one of “passed”, “failed”, “skipped”.

longrepr: Union[None, _pytest._code.code.ExceptionInfo[BaseException], Tuple[str, int, str], str, _pytest._code.code.TerminalRepr]

None or a failure representation.

result

The collected items and collection nodes.

sections: List[Tuple[str, str]]

Tuples of str (heading, content) with extra information for the test report. Used by pytest to add text captured from stdout, stderr, and intercepted logging events. May be used by other plugins to add arbitrary information to reports.

caplog

Return captured log lines, if log capturing is enabled.

New in version 3.5.

capstderr

Return captured text from stderr, if capturing is enabled.

New in version 3.0.

capstdout

Return captured text from stdout, if capturing is enabled.

New in version 3.0.

count_towards_summary

Experimental Whether this report should be counted towards the totals shown at the end of the test session: “1 passed, 1 failure, etc”.

Note

This function is considered experimental, so beware that it is subject to changes even in patch releases.

failed

Whether the outcome is failed.

fspath

The path portion of the reported node, as a string.

head_line

Experimental The head line shown with longrepr output for this report, more commonly during traceback representation during failures:

________ Test.foo ________

In the example above, the head_line is “Test.foo”.

Note

This function is considered experimental, so beware that it is subject to changes even in patch releases.

longreprtext

Read-only property that returns the full string representation of longrepr.

New in version 3.0.

passed

Whether the outcome is passed.

skipped

Whether the outcome is skipped.

Config

final class Config[source]

Access to configuration values, pluginmanager and plugin hooks.

Parameters
final class InvocationParams(args, plugins, dir)[source]

Holds parameters passed during pytest.main().

The object attributes are read-only.

New in version 5.1.

Note

Note that the environment variable PYTEST_ADDOPTS and the addopts ini option are handled by pytest, not being included in the args attribute.

Plugins accessing InvocationParams must be aware of that.

args: Tuple[str, ]

The command-line arguments as passed to pytest.main().

plugins: Optional[Sequence[Union[str, object]]]

Extra plugins, might be None.

dir: pathlib.Path

The directory from which pytest.main() was invoked.

option

Access to command line option as attributes.

Type

argparse.Namespace

invocation_params

The parameters with which pytest was invoked.

Type

InvocationParams

pluginmanager

The plugin manager handles plugin registration and hook invocation.

Type

PytestPluginManager

stash

A place where plugins can store information on the config for their own use.

Type

Stash

rootpath

The path to the rootdir.

Type

pathlib.Path

New in version 6.1.

inipath

The path to the configfile.

Type

Optional[pathlib.Path]

New in version 6.1.

add_cleanup(func)[source]

Add a function to be called when the config object gets out of use (usually coinciding with pytest_unconfigure).

Parameters

func (Callable[[], None]) –

Return type

None

classmethod fromdictargs(option_dict, args)[source]

Constructor usable for subprocesses.

Return type

_pytest.config.Config

issue_config_time_warning(warning, stacklevel)[source]

Issue and handle a warning during the “configure” stage.

During pytest_configure we can’t capture warnings using the catch_warnings_for_item function because it is not possible to have hookwrappers around pytest_configure.

This function is mainly intended for plugins that need to issue warnings during pytest_configure (or similar stages).

Parameters
  • warning (Warning) – The warning instance.

  • stacklevel (int) – stacklevel forwarded to warnings.warn.

Return type

None

addinivalue_line(name, line)[source]

Add a line to an ini-file option. The option must have been declared but might not yet be set in which case the line becomes the first line in its value.

Parameters
  • name (str) –

  • line (str) –

Return type

None

getini(name)[source]

Return configuration value from an ini file.

If the specified name hasn’t been registered through a prior parser.addini call (usually from a plugin), a ValueError is raised.

Parameters

name (str) –

getoption(name, default=<NOTSET>, skip=False)[source]

Return command line option value.

Parameters
  • name (str) – Name of the option. You may also specify the literal --OPT option instead of the “dest” option name.

  • default – Default value if no option of that name exists.

  • skip (bool) – If True, raise pytest.skip if option does not exists or has a None value.

getvalue(name, path=None)[source]

Deprecated, use getoption() instead.

Parameters

name (str) –

getvalueorskip(name, path=None)[source]

Deprecated, use getoption(skip=True) instead.

Parameters

name (str) –

ExceptionInfo

final class ExceptionInfo[source]

Wraps sys.exc_info() objects and offers help for navigating the traceback.

classmethod from_exc_info(exc_info, exprinfo=None)[source]

Return an ExceptionInfo for an existing exc_info tuple.

Warning

Experimental API

Parameters
  • exprinfo (Optional[str]) – A text string helping to determine if we should strip AssertionError from the output. Defaults to the exception message/__str__().

  • exc_info (Tuple[Type[E], E, traceback]) –

Return type

_pytest._code.code.ExceptionInfo[E]

classmethod from_current(exprinfo=None)[source]

Return an ExceptionInfo matching the current traceback.

Warning

Experimental API

Parameters

exprinfo (Optional[str]) – A text string helping to determine if we should strip AssertionError from the output. Defaults to the exception message/__str__().

Return type

_pytest._code.code.ExceptionInfo[BaseException]

classmethod for_later()[source]

Return an unfilled ExceptionInfo.

Return type

_pytest._code.code.ExceptionInfo[E]

fill_unfilled(exc_info)[source]

Fill an unfilled ExceptionInfo created with for_later().

Parameters

exc_info (Tuple[Type[E], E, traceback]) –

Return type

None

type

The exception class.

value

The exception value.

tb

The exception raw traceback.

typename

The type name of the exception.

traceback

The traceback.

exconly(tryshort=False)[source]

Return the exception as a string.

When ‘tryshort’ resolves to True, and the exception is an AssertionError, only the actual exception part of the exception representation is returned (so ‘AssertionError: ‘ is removed from the beginning).

Parameters

tryshort (bool) –

Return type

str

errisinstance(exc)[source]

Return True if the exception is an instance of exc.

Consider using isinstance(excinfo.value, exc) instead.

Parameters

exc (Union[Type[BaseException], Tuple[Type[BaseException], ..]]) –

Return type

bool

getrepr(showlocals=False, style='long', abspath=False, tbfilter=True, funcargs=False, truncate_locals=True, chain=True)[source]

Return str()able representation of this exception info.

Parameters
  • showlocals (bool) – Show locals per traceback entry. Ignored if style=="native".

  • style (str) – long|short|no|native|value traceback style.

  • abspath (bool) – If paths should be changed to absolute or left unchanged.

  • tbfilter (bool) – Hide entries that contain a local variable __tracebackhide__==True. Ignored if style=="native".

  • funcargs (bool) – Show fixtures (“funcargs” for legacy purposes) per traceback entry.

  • truncate_locals (bool) – With showlocals==True, make sure locals can be safely represented as strings.

  • chain (bool) – If chained exceptions in Python 3 should be shown.

Return type

Union[ReprExceptionInfo, ExceptionChainRepr]

Changed in version 3.9: Added the chain parameter.

match(regexp)[source]

Check whether the regular expression regexp matches the string representation of the exception using re.search().

If it matches True is returned, otherwise an AssertionError is raised.

Parameters

regexp (Union[str, Pattern[str]]) –

Return type

Literal[True]

ExitCode

final class ExitCode(value)[source]

Encodes the valid exit codes by pytest.

Currently users and plugins may supply other exit codes as well.

New in version 5.0.

OK = 0

Tests passed.

TESTS_FAILED = 1

Tests failed.

INTERRUPTED = 2

pytest was interrupted.

INTERNAL_ERROR = 3

An internal error got in the way.

USAGE_ERROR = 4

pytest was misused.

NO_TESTS_COLLECTED = 5

pytest couldn’t find tests.

File

class File[source]

Bases: _pytest.nodes.FSCollector

Base class for collecting tests from a file.

Working with non-python tests.

FixtureDef

final class FixtureDef[source]

Bases: Generic[_pytest.fixtures.FixtureValue]

A container for a fixture definition.

scope

Scope string, one of “function”, “class”, “module”, “package”, “session”.

FSCollector

class FSCollector[source]

Bases: _pytest.nodes.Collector

classmethod from_parent(parent, *, fspath=None, path=None, **kw)[source]

The public constructor.

Parameters
  • fspath (Optional[py._path.local.LocalPath]) –

  • path (Optional[pathlib.Path]) –

Function

class Function[source]

Bases: _pytest.python.PyobjMixin, _pytest.nodes.Item

An Item responsible for setting up and executing a Python test function.

Parameters
  • name – The full function name, including any decorations like those added by parametrization (my_func[my_param]).

  • parent – The parent Node.

  • config – The pytest Config object.

  • callspec – If given, this is function has been parametrized and the callspec contains meta information about the parametrization.

  • callobj – If given, the object which will be called when the Function is invoked, otherwise the callobj will be obtained from parent using originalname.

  • keywords – Keywords bound to the function object for “-k” matching.

  • session – The pytest Session object.

  • fixtureinfo – Fixture information already resolved at this fixture node..

  • originalname – The attribute name to use for accessing the underlying function object. Defaults to name. Set this if name is different from the original name, for example when it contains decorations like those added by parametrization (my_func[my_param]).

originalname

Original function name, without any decorations (for example parametrization adds a "[...]" suffix to function names), used to access the underlying function object from parent (in case callobj is not given explicitly).

New in version 3.0.

classmethod from_parent(parent, **kw)[source]

The public constructor.

function

Underlying python ‘function’ object.

runtest()[source]

Execute the underlying test function.

Return type

None

repr_failure(excinfo)[source]

Return a representation of a collection or test failure.

Parameters

excinfo (_pytest._code.code.ExceptionInfo[BaseException]) – Exception information for the failure.

Return type

Union[str, _pytest._code.code.TerminalRepr]

FunctionDefinition

class FunctionDefinition[source]

Bases: _pytest.python.Function

This class is a step gap solution until we evolve to have actual function definition nodes and manage to get rid of metafunc.

runtest()[source]

Execute the underlying test function.

Return type

None

setup()

Execute the underlying test function.

Return type

None

Item

class Item[source]

Bases: _pytest.nodes.Node

A basic test invocation item.

Note that for a single function there might be multiple test invocation items.

user_properties: List[Tuple[str, object]]

A list of tuples (name, value) that holds user defined properties for this test.

runtest()[source]

Run the test case for this item.

Must be implemented by subclasses.

Return type

None

add_report_section(when, key, content)[source]

Add a new report section, similar to what’s done internally to add stdout and stderr captured output:

item.add_report_section("call", "stdout", "report section contents")
Parameters
  • when (str) – One of the possible capture states, "setup", "call", "teardown".

  • key (str) – Name of the section, can be customized at will. Pytest uses "stdout" and "stderr" internally.

  • content (str) – The full contents as a string.

Return type

None

reportinfo()[source]

Get location information for this item for test reports.

Returns a tuple with three elements:

  • The path of the test (default self.path)

  • The line number of the test (default None)

  • A name of the test to be shown (default "")

Return type

Tuple[Union[os.PathLike[str], str], Optional[int], str]

MarkDecorator

class MarkDecorator[source]

A decorator for applying a mark on test functions and classes.

MarkDecorators are created with pytest.mark:

mark1 = pytest.mark.NAME              # Simple MarkDecorator
mark2 = pytest.mark.NAME(name1=value) # Parametrized MarkDecorator

and can then be applied as decorators to test functions:

@mark2
def test_function():
    pass

When a MarkDecorator is called, it does the following:

  1. If called with a single class as its only positional argument and no additional keyword arguments, it attaches the mark to the class so it gets applied automatically to all test cases found in that class.

  2. If called with a single function as its only positional argument and no additional keyword arguments, it attaches the mark to the function, containing all the arguments already stored internally in the MarkDecorator.

  3. When called in any other case, it returns a new MarkDecorator instance with the original MarkDecorator’s content updated with the arguments passed to this call.

Note: The rules above prevent a MarkDecorator from storing only a single function or class reference as its positional argument with no additional keyword or positional arguments. You can work around this by using with_args().

name

Alias for mark.name.

args

Alias for mark.args.

kwargs

Alias for mark.kwargs.

with_args(*args, **kwargs)[source]

Return a MarkDecorator with extra arguments added.

Unlike calling the MarkDecorator, with_args() can be used even if the sole argument is a callable/class.

Parameters
Return type

_pytest.mark.structures.MarkDecorator

MarkGenerator

final class MarkGenerator[source]

Factory for MarkDecorator objects - exposed as a pytest.mark singleton instance.

Example:

import pytest

@pytest.mark.slowtest
def test_function():
   pass

applies a ‘slowtest’ Mark on test_function.

Mark

final class Mark[source]
name: str

Name of the mark.

args: Tuple[Any, ]

Positional arguments of the mark decorator.

kwargs: Mapping[str, Any]

Keyword arguments of the mark decorator.

combined_with(other)[source]

Return a new Mark which is a combination of this Mark and another Mark.

Combines by appending args and merging kwargs.

Parameters

other (Mark) – The mark to combine with.

Return type

Mark

Metafunc

final class Metafunc[source]

Objects passed to the pytest_generate_tests hook.

They help to inspect a test function and to generate tests according to test configuration or values specified in the class or module where a test function is defined.

definition

Access to the underlying _pytest.python.FunctionDefinition.

config

Access to the pytest.Config object for the test session.

module

The module object where the test function is defined in.

function

Underlying Python test function.

fixturenames

Set of fixture names required by the test function.

cls

Class object where the test function is defined in or None.

parametrize(argnames, argvalues, indirect=False, ids=None, scope=None, *, _param_mark=None)[source]

Add new invocations to the underlying test function using the list of argvalues for the given argnames. Parametrization is performed during the collection phase. If you need to setup expensive resources see about setting indirect to do it rather than at test setup time.

Can be called multiple times, in which case each call parametrizes all previous parametrizations, e.g.

unparametrized:         t
parametrize ["x", "y"]: t[x], t[y]
parametrize [1, 2]:     t[x-1], t[x-2], t[y-1], t[y-2]
Parameters
  • argnames (Union[str, List[str], Tuple[str, ..]]) – A comma-separated string denoting one or more argument names, or a list/tuple of argument strings.

  • argvalues (Iterable[Union[_pytest.mark.structures.ParameterSet, Sequence[object], object]]) –

    The list of argvalues determines how often a test is invoked with different argument values.

    If only one argname was specified argvalues is a list of values. If N argnames were specified, argvalues must be a list of N-tuples, where each tuple-element specifies a value for its respective argname.

  • indirect (Union[bool, Sequence[str]]) – A list of arguments’ names (subset of argnames) or a boolean. If True the list contains all names from the argnames. Each argvalue corresponding to an argname in this list will be passed as request.param to its respective argname fixture function so that it can perform more expensive setups during the setup phase of a test rather than at collection time.

  • ids (Optional[Union[Iterable[Optional[object]], Callable[[Any], Optional[object]]]]) –

    Sequence of (or generator for) ids for argvalues, or a callable to return part of the id for each argvalue.

    With sequences (and generators like itertools.count()) the returned ids should be of type string, int, float, bool, or None. They are mapped to the corresponding index in argvalues. None means to use the auto-generated id.

    If it is a callable it will be called for each entry in argvalues, and the return value is used as part of the auto-generated id for the whole set (where parts are joined with dashes (“-“)). This is useful to provide more specific ids for certain items, e.g. dates. Returning None will use an auto-generated id.

    If no ids are provided they will be generated automatically from the argvalues.

  • scope (Optional[_ScopeName]) – If specified it denotes the scope of the parameters. The scope is used for grouping tests by parameter instances. It will also override any fixture-function defined scope, allowing to set a dynamic scope using test context or configuration.

  • _param_mark (Optional[_pytest.mark.structures.Mark]) –

Return type

None

Module

class Module[source]

Bases: _pytest.nodes.File, _pytest.python.PyCollector

Collector for test classes and functions.

collect()[source]

Return a list of children (items and collectors) for this collection node.

Return type

Iterable[Union[_pytest.nodes.Item, _pytest.nodes.Collector]]

Node

class Node[source]

Base class for Collector and Item, the components of the test collection tree.

Collector subclasses have children; Items are leaf nodes.

fspath: py._path.local.LocalPath

A LEGACY_PATH copy of the path attribute. Intended for usage for methods not migrated to pathlib.Path yet, such as Item.reportinfo(). Will be deprecated in a future release, prefer using path instead.

name

A unique name within the scope of the parent node.

parent

The parent collector node.

config

The pytest config object.

session

The pytest session this node is part of.

path

Filesystem path where this node was collected from (can be None).

keywords: MutableMapping[str, Any]

Keywords/markers collected from all scopes.

own_markers: List[_pytest.mark.structures.Mark]

The marker objects belonging to this node.

extra_keyword_matches: Set[str]

Allow adding of extra keywords to use for matching.

stash

A place where plugins can store information on the node for their own use.

Type

Stash

classmethod from_parent(parent, **kw)[source]

Public constructor for Nodes.

This indirection got introduced in order to enable removing the fragile logic from the node constructors.

Subclasses can use super().from_parent(...) when overriding the construction.

Parameters

parent (_pytest.nodes.Node) – The parent node of this Node.

ihook

fspath-sensitive hook proxy used to call pytest hooks.

warn(warning)[source]

Issue a warning for this Node.

Warnings will be displayed after the test session, unless explicitly suppressed.

Parameters

warning (Warning) – The warning instance to issue.

Raises

ValueError – If warning instance is not a subclass of Warning.

Return type

None

Example usage:

node.warn(PytestWarning("some message"))
node.warn(UserWarning("some message"))

Changed in version 6.2: Any subclass of Warning is now accepted, rather than only PytestWarning subclasses.

nodeid

A ::-separated string denoting its collection tree address.

listchain()[source]

Return list of all parent collectors up to self, starting from the root of collection tree.

Return type

List[_pytest.nodes.Node]

add_marker(marker, append=True)[source]

Dynamically add a marker object to the node.

Parameters
  • append (bool) – Whether to append the marker, or prepend it.

  • marker (Union[str, _pytest.mark.structures.MarkDecorator]) –

Return type

None

iter_markers(name=None)[source]

Iterate over all markers of the node.

Parameters

name (Optional[str]) – If given, filter the results by the name attribute.

Return type

Iterator[_pytest.mark.structures.Mark]

for ... in iter_markers_with_node(name=None)[source]

Iterate over all markers of the node.

Parameters

name (Optional[str]) – If given, filter the results by the name attribute.

Returns

An iterator of (node, mark) tuples.

Return type

Iterator[Tuple[_pytest.nodes.Node, _pytest.mark.structures.Mark]]

get_closest_marker(name, default=None)[source]

Return the first marker matching the name, from closest (for example function) to farther level (for example module level).

Parameters
  • default (Optional[_pytest.mark.structures.Mark]) – Fallback return value if no marker was found.

  • name (str) – Name to filter by.

Return type

Optional[_pytest.mark.structures.Mark]

listextrakeywords()[source]

Return a set of all extra keywords in self and any parents.

Return type

Set[str]

addfinalizer(fin)[source]

Register a function to be called when this node is finalized.

This method can only be called when this node is active in a setup chain, for example during self.setup().

Parameters

fin (Callable[[], object]) –

Return type

None

getparent(cls)[source]

Get the next parent node (including self) which is an instance of the given class.

Parameters

cls (Type[_NodeType]) –

Return type

Optional[_NodeType]

repr_failure(excinfo, style=None)[source]

Return a representation of a collection or test failure.

Parameters
  • excinfo (_pytest._code.code.ExceptionInfo[BaseException]) – Exception information for the failure.

  • style (Optional[_TracebackStyle]) –

Return type

Union[str, _pytest._code.code.TerminalRepr]

Parser

final class Parser[source]

Parser for command line arguments and ini-file values.

Variables

extra_info – Dict of generic param -> value to display in case there’s an error processing the command line arguments.

getgroup(name, description='', after=None)[source]

Get (or create) a named option Group.

Name

Name of the option group.

Description

Long description for –help output.

After

Name of another group, used for ordering –help output.

Parameters
  • name (str) –

  • description (str) –

  • after (Optional[str]) –

Return type

_pytest.config.argparsing.OptionGroup

The returned group object has an addoption method with the same signature as parser.addoption but will be shown in the respective group in the output of pytest. --help.

addoption(*opts, **attrs)[source]

Register a command line option.

Opts

Option names, can be short or long options.

Attrs

Same attributes which the add_argument() function of the argparse library accepts.

Parameters
  • opts (str) –

  • attrs (Any) –

Return type

None

After command line parsing, options are available on the pytest config object via config.option.NAME where NAME is usually set by passing a dest attribute, for example addoption("--long", dest="NAME", ...).

parse_known_args(args, namespace=None)[source]

Parse and return a namespace object with known arguments at this point.

Parameters
Return type

argparse.Namespace

parse_known_and_unknown_args(args, namespace=None)[source]

Parse and return a namespace object with known arguments, and the remaining arguments unknown at this point.

Parameters
Return type

Tuple[argparse.Namespace, List[str]]

addini(name, help, type=None, default=None)[source]

Register an ini-file option.

Name

Name of the ini-variable.

Type

Type of the variable. Can be:

  • string: a string

  • bool: a boolean

  • args: a list of strings, separated as in a shell

  • linelist: a list of strings, separated by line breaks

  • paths: a list of pathlib.Path, separated as in a shell

  • pathlist: a list of py.path, separated as in a shell

New in version 7.0: The paths variable type.

Defaults to string if None or not passed.

Default

Default value if no ini-file option exists but is queried.

Parameters
  • name (str) –

  • help (str) –

  • type (Optional[Literal['string', 'paths', 'pathlist', 'args', 'linelist', 'bool']]) –

Return type

None

The value of ini-variables can be retrieved via a call to config.getini(name).

OptionGroup

class OptionGroup[source]

A group of options shown in its own section.

addoption(*optnames, **attrs)[source]

Add an option to this group.

If a shortened version of a long option is specified, it will be suppressed in the help. addoption('--twowords', '--two-words') results in help showing --two-words only, but --twowords gets accepted and the automatic destination is in args.twowords.

Parameters
  • optnames (str) –

  • attrs (Any) –

Return type

None

PytestPluginManager

final class PytestPluginManager[source]

Bases: pluggy._manager.PluginManager

A pluggy.PluginManager with additional pytest-specific functionality:

  • Loading plugins from the command line, PYTEST_PLUGINS env variable and pytest_plugins global variables found in plugins being loaded.

  • conftest.py loading during start-up.

parse_hookimpl_opts(plugin, name)[source]
Parameters
parse_hookspec_opts(module_or_class, name)[source]
Parameters

name (str) –

register(plugin, name=None)[source]

Register a plugin and return its canonical name or None if the name is blocked from registering. Raise a ValueError if the plugin is already registered.

Parameters
  • plugin (object) –

  • name (Optional[str]) –

Return type

Optional[str]

getplugin(name)[source]
Parameters

name (str) –

hasplugin(name)[source]

Return whether a plugin with the given name is registered.

Parameters

name (str) –

Return type

bool

import_plugin(modname, consider_entry_points=False)[source]

Import a plugin with modname.

If consider_entry_points is True, entry point names are also considered to find a plugin.

Parameters
  • modname (str) –

  • consider_entry_points (bool) –

Return type

None

add_hookcall_monitoring(before, after)

add before/after tracing functions for all hooks and return an undo function which, when called, will remove the added tracers.

before(hook_name, hook_impls, kwargs) will be called ahead of all hook calls and receive a hookcaller instance, a list of HookImpl instances and the keyword arguments for the hook call.

after(outcome, hook_name, hook_impls, kwargs) receives the same arguments as before but also a pluggy._callers._Result object which represents the result of the overall hook call.

add_hookspecs(module_or_class)

add new hook specifications defined in the given module_or_class. Functions are recognized if they have been decorated accordingly.

check_pending()

Verify that all hooks which have not been verified against a hook specification are optional, otherwise raise PluginValidationError.

enable_tracing()

enable tracing of hook calls and return an undo function.

get_canonical_name(plugin)

Return canonical name for a plugin object. Note that a plugin may be registered under a different name which was specified by the caller of register(plugin, name). To obtain the name of an registered plugin use get_name(plugin) instead.

get_hookcallers(plugin)

get all hook callers for the specified plugin.

get_name(plugin)

Return name for registered plugin or None if not registered.

get_plugin(name)

Return a plugin or None for the given name.

get_plugins()

return the set of registered plugins.

has_plugin(name)

Return True if a plugin with the given name is registered.

is_blocked(name)

return True if the given plugin name is blocked.

is_registered(plugin)

Return True if the plugin is already registered.

list_name_plugin()

return list of name/plugin pairs.

list_plugin_distinfo()

return list of distinfo/plugin tuples for all setuptools registered plugins.

load_setuptools_entrypoints(group, name=None)

Load modules from querying the specified setuptools group.

Parameters
  • group (str) – entry point group to load plugins

  • name (str) – if given, loads only plugins with the given name.

Return type

int

Returns

return the number of loaded plugins by this call.

set_blocked(name)

block registrations of the given name, unregister if already registered.

subset_hook_caller(name, remove_plugins)

Return a new _hooks._HookCaller instance for the named method which manages calls to all registered plugins except the ones from remove_plugins.

unregister(plugin=None, name=None)

unregister a plugin object and all its contained hook implementations from internal data structures.

Session

final class Session[source]

Bases: _pytest.nodes.FSCollector

exception Interrupted

Bases: KeyboardInterrupt

Signals that the test run was interrupted.

exception Failed

Bases: Exception

Signals a stop as failed test run.

startpath

The path from which pytest was invoked.

New in version 7.0.0.

perform_collect(args=None, genitems=True)[source]

Perform the collection phase for this session.

This is called by the default pytest_collection hook implementation; see the documentation of this hook for more details. For testing purposes, it may also be called directly on a fresh Session.

This function normally recursively expands any collectors collected from the session to their items, and only items are returned. For testing purposes, this may be suppressed by passing genitems=False, in which case the return value contains these collectors unexpanded, and session.items is empty.

Parameters
  • args (Optional[Sequence[str]]) –

  • genitems (bool) –

Return type

Sequence[Union[_pytest.nodes.Item, _pytest.nodes.Collector]]

for ... in collect()[source]

Return a list of children (items and collectors) for this collection node.

Return type

Iterator[Union[_pytest.nodes.Item, _pytest.nodes.Collector]]

TestReport

final class TestReport[source]

Bases: _pytest.reports.BaseReport

Basic test report object (also used for setup and teardown calls if they fail).

Reports can contain arbitrary extra attributes.

nodeid: str

Normalized collection nodeid.

location: Optional[Tuple[str, Optional[int], str]]

A (filesystempath, lineno, domaininfo) tuple indicating the actual location of a test item - it might be different from the collected one e.g. if a method is inherited from a different module.

keywords

A name -> value dictionary containing all keywords and markers associated with a test invocation.

outcome: Literal[passed, failed, skipped]

Test outcome, always one of “passed”, “failed”, “skipped”.

longrepr: Union[None, _pytest._code.code.ExceptionInfo[BaseException], Tuple[str, int, str], str, _pytest._code.code.TerminalRepr]

None or a failure representation.

when: Optional[str]

One of ‘setup’, ‘call’, ‘teardown’ to indicate runtest phase.

user_properties

User properties is a list of tuples (name, value) that holds user defined properties of the test.

sections: List[Tuple[str, str]]

Tuples of str (heading, content) with extra information for the test report. Used by pytest to add text captured from stdout, stderr, and intercepted logging events. May be used by other plugins to add arbitrary information to reports.

duration

Time it took to run just the test.

classmethod from_item_and_call(item, call)[source]

Create and fill a TestReport with standard item and call info.

Parameters
Return type

TestReport

caplog

Return captured log lines, if log capturing is enabled.

New in version 3.5.

capstderr

Return captured text from stderr, if capturing is enabled.

New in version 3.0.

capstdout

Return captured text from stdout, if capturing is enabled.

New in version 3.0.

count_towards_summary

Experimental Whether this report should be counted towards the totals shown at the end of the test session: “1 passed, 1 failure, etc”.

Note

This function is considered experimental, so beware that it is subject to changes even in patch releases.

failed

Whether the outcome is failed.

fspath

The path portion of the reported node, as a string.

head_line

Experimental The head line shown with longrepr output for this report, more commonly during traceback representation during failures:

________ Test.foo ________

In the example above, the head_line is “Test.foo”.

Note

This function is considered experimental, so beware that it is subject to changes even in patch releases.

longreprtext

Read-only property that returns the full string representation of longrepr.

New in version 3.0.

passed

Whether the outcome is passed.

skipped

Whether the outcome is skipped.

_Result

Result object used within hook wrappers, see _Result in the pluggy documentation for more information.

Stash

class Stash[source]

Stash is a type-safe heterogeneous mutable mapping that allows keys and value types to be defined separately from where it (the Stash) is created.

Usually you will be given an object which has a Stash, for example Config or a Node:

stash: Stash = some_object.stash

If a module or plugin wants to store data in this Stash, it creates StashKeys for its keys (at the module level):

# At the top-level of the module
some_str_key = StashKey[str]()
some_bool_key = StashKey[bool]()

To store information:

# Value type must match the key.
stash[some_str_key] = "value"
stash[some_bool_key] = True

To retrieve the information:

# The static type of some_str is str.
some_str = stash[some_str_key]
# The static type of some_bool is bool.
some_bool = stash[some_bool_key]
__setitem__(key, value)[source]

Set a value for key.

Parameters
  • key (_pytest.stash.StashKey[T]) –

  • value (T) –

Return type

None

__getitem__(key)[source]

Get the value for key.

Raises KeyError if the key wasn’t set before.

Parameters

key (_pytest.stash.StashKey[T]) –

Return type

T

get(key, default)[source]

Get the value for key, or return default if the key wasn’t set before.

Parameters
  • key (_pytest.stash.StashKey[T]) –

  • default (D) –

Return type

Union[T, D]

setdefault(key, default)[source]

Return the value of key if already set, otherwise set the value of key to default and return default.

Parameters
  • key (_pytest.stash.StashKey[T]) –

  • default (T) –

Return type

T

__delitem__(key)[source]

Delete the value for key.

Raises KeyError if the key wasn’t set before.

Parameters

key (_pytest.stash.StashKey[T]) –

Return type

None

__contains__(key)[source]

Return whether key was set.

Parameters

key (_pytest.stash.StashKey[T]) –

Return type

bool

__len__()[source]

Return how many items exist in the stash.

Return type

int

class StashKey[source]

Bases: Generic[_pytest.stash.T]

StashKey is an object used as a key to a Stash.

A StashKey is associated with the type T of the value of the key.

A StashKey is unique and cannot conflict with another key.

Global Variables

pytest treats some global variables in a special manner when defined in a test module or conftest.py files.

collect_ignore

Tutorial: Customizing test collection

Can be declared in conftest.py files to exclude test directories or modules. Needs to be a list of paths (str, pathlib.Path or any os.PathLike).

collect_ignore = ["setup.py"]
collect_ignore_glob

Tutorial: Customizing test collection

Can be declared in conftest.py files to exclude test directories or modules with Unix shell-style wildcards. Needs to be list[str] where str can contain glob patterns.

collect_ignore_glob = ["*_ignore.py"]
pytest_plugins

Tutorial: Requiring/Loading plugins in a test module or conftest file

Can be declared at the global level in test modules and conftest.py files to register additional plugins. Can be either a str or Sequence[str].

pytest_plugins = "myapp.testsupport.myplugin"
pytest_plugins = ("myapp.testsupport.tools", "myapp.testsupport.regression")
pytestmark

Tutorial: Marking whole classes or modules

Can be declared at the global level in test modules to apply one or more marks to all test functions and methods. Can be either a single mark or a list of marks (applied in left-to-right order).

import pytest

pytestmark = pytest.mark.webtest
import pytest

pytestmark = [pytest.mark.integration, pytest.mark.slow]

Environment Variables

Environment variables that can be used to change pytest’s behavior.

PYTEST_ADDOPTS

This contains a command-line (parsed by the py:mod:shlex module) that will be prepended to the command line given by the user, see Builtin configuration file options for more information.

PYTEST_CURRENT_TEST

This is not meant to be set by users, but is set by pytest internally with the name of the current test so other processes can inspect it, see PYTEST_CURRENT_TEST environment variable for more information.

PYTEST_DEBUG

When set, pytest will print tracing and debug information.

PYTEST_DISABLE_PLUGIN_AUTOLOAD

When set, disables plugin auto-loading through setuptools entrypoints. Only explicitly specified plugins will be loaded.

PYTEST_PLUGINS

Contains comma-separated list of modules that should be loaded as plugins:

export PYTEST_PLUGINS=mymodule.plugin,xdist
PYTEST_THEME

Sets a pygment style to use for the code output.

PYTEST_THEME_MODE

Sets the PYTEST_THEME to be either dark or light.

PY_COLORS

When set to 1, pytest will use color in terminal output. When set to 0, pytest will not use color. PY_COLORS takes precedence over NO_COLOR and FORCE_COLOR.

NO_COLOR

When set (regardless of value), pytest will not use color in terminal output. PY_COLORS takes precedence over NO_COLOR, which takes precedence over FORCE_COLOR. See no-color.org for other libraries supporting this community standard.

FORCE_COLOR

When set (regardless of value), pytest will use color in terminal output. PY_COLORS and NO_COLOR take precedence over FORCE_COLOR.

Exceptions

final class UsageError[source]

Bases: Exception

Error in pytest usage or invocation.

Warnings

Custom warnings generated in some situations such as improper usage or deprecated features.

class PytestWarning

Bases: UserWarning

Base class for all warnings emitted by pytest.

class PytestAssertRewriteWarning

Bases: pytest.PytestWarning

Warning emitted by the pytest assert rewrite module.

class PytestCacheWarning

Bases: pytest.PytestWarning

Warning emitted by the cache plugin in various situations.

class PytestCollectionWarning

Bases: pytest.PytestWarning

Warning emitted when pytest is not able to collect a file or symbol in a module.

class PytestConfigWarning

Bases: pytest.PytestWarning

Warning emitted for configuration issues.

class PytestDeprecationWarning

Bases: pytest.PytestWarning, DeprecationWarning

Warning class for features that will be removed in a future version.

class PytestExperimentalApiWarning

Bases: pytest.PytestWarning, FutureWarning

Warning category used to denote experiments in pytest.

Use sparingly as the API might change or even be removed completely in a future version.

class PytestUnhandledCoroutineWarning

Bases: pytest.PytestWarning

Warning emitted for an unhandled coroutine.

A coroutine was encountered when collecting test functions, but was not handled by any async-aware plugin. Coroutine test functions are not natively supported.

class PytestUnknownMarkWarning

Bases: pytest.PytestWarning

Warning emitted on use of unknown markers.

See How to mark test functions with attributes for details.

class PytestUnraisableExceptionWarning

Bases: pytest.PytestWarning

An unraisable exception was reported.

Unraisable exceptions are exceptions raised in __del__ implementations and similar situations when the exception cannot be raised as normal.

class PytestUnhandledThreadExceptionWarning

Bases: pytest.PytestWarning

An unhandled exception occurred in a Thread.

Such exceptions don’t propagate normally.

Consult the Internal pytest warnings section in the documentation for more information.

Configuration Options

Here is a list of builtin configuration options that may be written in a pytest.ini, pyproject.toml, tox.ini or setup.cfg file, usually located at the root of your repository. To see each file format in details, see Configuration file formats.

Warning

Usage of setup.cfg is not recommended except for very simple use cases. .cfg files use a different parser than pytest.ini and tox.ini which might cause hard to track down problems. When possible, it is recommended to use the latter files, or pyproject.toml, to hold your pytest configuration.

Configuration options may be overwritten in the command-line by using -o/--override-ini, which can also be passed multiple times. The expected format is name=value. For example:

pytest -o console_output_style=classic -o cache_dir=/tmp/mycache
addopts

Add the specified OPTS to the set of command line arguments as if they had been specified by the user. Example: if you have this ini file content:

# content of pytest.ini
[pytest]
addopts = --maxfail=2 -rf  # exit after 2 failures, report fail info

issuing pytest test_hello.py actually means:

pytest --maxfail=2 -rf test_hello.py

Default is to add no options.

cache_dir

Sets a directory where stores content of cache plugin. Default directory is .pytest_cache which is created in rootdir. Directory may be relative or absolute path. If setting relative path, then directory is created relative to rootdir. Additionally path may contain environment variables, that will be expanded. For more information about cache plugin please refer to How to re-run failed tests and maintain state between test runs.

console_output_style

Sets the console output style while running tests:

  • classic: classic pytest output.

  • progress: like classic pytest output, but with a progress indicator.

  • count: like progress, but shows progress as the number of tests completed instead of a percent.

The default is progress, but you can fallback to classic if you prefer or the new mode is causing unexpected problems:

# content of pytest.ini
[pytest]
console_output_style = classic
doctest_encoding

Default encoding to use to decode text files with docstrings. See how pytest handles doctests.

doctest_optionflags

One or more doctest flag names from the standard doctest module. See how pytest handles doctests.

empty_parameter_set_mark

Allows to pick the action for empty parametersets in parameterization

  • skip skips tests with an empty parameterset (default)

  • xfail marks tests with an empty parameterset as xfail(run=False)

  • fail_at_collect raises an exception if parametrize collects an empty parameter set

# content of pytest.ini
[pytest]
empty_parameter_set_mark = xfail

Note

The default value of this option is planned to change to xfail in future releases as this is considered less error prone, see issue #3155 for more details.

faulthandler_timeout

Dumps the tracebacks of all threads if a test takes longer than X seconds to run (including fixture setup and teardown). Implemented using the faulthandler.dump_traceback_later() function, so all caveats there apply.

# content of pytest.ini
[pytest]
faulthandler_timeout=5

For more information please refer to Fault Handler.

filterwarnings

Sets a list of filters and actions that should be taken for matched warnings. By default all warnings emitted during the test session will be displayed in a summary at the end of the test session.

# content of pytest.ini
[pytest]
filterwarnings =
    error
    ignore::DeprecationWarning

This tells pytest to ignore deprecation warnings and turn all other warnings into errors. For more information please refer to How to capture warnings.

junit_duration_report

New in version 4.1.

Configures how durations are recorded into the JUnit XML report:

  • total (the default): duration times reported include setup, call, and teardown times.

  • call: duration times reported include only call times, excluding setup and teardown.

[pytest]
junit_duration_report = call
junit_family

New in version 4.2.

Changed in version 6.1: Default changed to xunit2.

Configures the format of the generated JUnit XML file. The possible options are:

  • xunit1 (or legacy): produces old style output, compatible with the xunit 1.0 format.

  • xunit2: produces xunit 2.0 style output, which should be more compatible with latest Jenkins versions. This is the default.

[pytest]
junit_family = xunit2
junit_logging

New in version 3.5.

Changed in version 5.4: log, all, out-err options added.

Configures if captured output should be written to the JUnit XML file. Valid values are:

  • log: write only logging captured output.

  • system-out: write captured stdout contents.

  • system-err: write captured stderr contents.

  • out-err: write both captured stdout and stderr contents.

  • all: write captured logging, stdout and stderr contents.

  • no (the default): no captured output is written.

[pytest]
junit_logging = system-out
junit_log_passing_tests

New in version 4.6.

If junit_logging != "no", configures if the captured output should be written to the JUnit XML file for passing tests. Default is True.

[pytest]
junit_log_passing_tests = False
junit_suite_name

To set the name of the root test suite xml item, you can configure the junit_suite_name option in your config file:

[pytest]
junit_suite_name = my_suite
log_auto_indent

Allow selective auto-indentation of multiline log messages.

Supports command line option --log-auto-indent [value] and config option log_auto_indent = [value] to set the auto-indentation behavior for all logging.

[value] can be:
  • True or “On” - Dynamically auto-indent multiline log messages

  • False or “Off” or 0 - Do not auto-indent multiline log messages (the default behavior)

  • [positive integer] - auto-indent multiline log messages by [value] spaces

[pytest]
log_auto_indent = False

Supports passing kwarg extra={"auto_indent": [value]} to calls to logging.log() to specify auto-indentation behavior for a specific entry in the log. extra kwarg overrides the value specified on the command line or in the config.

log_cli

Enable log display during test run (also known as “live logging”). The default is False.

[pytest]
log_cli = True
log_cli_date_format

Sets a time.strftime()-compatible string that will be used when formatting dates for live logging.

[pytest]
log_cli_date_format = %Y-%m-%d %H:%M:%S

For more information, see Live Logs.

log_cli_format

Sets a logging-compatible string used to format live logging messages.

[pytest]
log_cli_format = %(asctime)s %(levelname)s %(message)s

For more information, see Live Logs.

log_cli_level

Sets the minimum log message level that should be captured for live logging. The integer value or the names of the levels can be used.

[pytest]
log_cli_level = INFO

For more information, see Live Logs.

log_date_format

Sets a time.strftime()-compatible string that will be used when formatting dates for logging capture.

[pytest]
log_date_format = %Y-%m-%d %H:%M:%S

For more information, see How to manage logging.

log_file

Sets a file name relative to the current working directory where log messages should be written to, in addition to the other logging facilities that are active.

[pytest]
log_file = logs/pytest-logs.txt

For more information, see How to manage logging.

log_file_date_format

Sets a time.strftime()-compatible string that will be used when formatting dates for the logging file.

[pytest]
log_file_date_format = %Y-%m-%d %H:%M:%S

For more information, see How to manage logging.

log_file_format

Sets a logging-compatible string used to format logging messages redirected to the logging file.

[pytest]
log_file_format = %(asctime)s %(levelname)s %(message)s

For more information, see How to manage logging.

log_file_level

Sets the minimum log message level that should be captured for the logging file. The integer value or the names of the levels can be used.

[pytest]
log_file_level = INFO

For more information, see How to manage logging.

log_format

Sets a logging-compatible string used to format captured logging messages.

[pytest]
log_format = %(asctime)s %(levelname)s %(message)s

For more information, see How to manage logging.

log_level

Sets the minimum log message level that should be captured for logging capture. The integer value or the names of the levels can be used.

[pytest]
log_level = INFO

For more information, see How to manage logging.

markers

When the --strict-markers or --strict command-line arguments are used, only known markers - defined in code by core pytest or some plugin - are allowed.

You can list additional markers in this setting to add them to the whitelist, in which case you probably want to add --strict-markers to addopts to avoid future regressions:

[pytest]
addopts = --strict-markers
markers =
    slow
    serial

Note

The use of --strict-markers is highly preferred. --strict was kept for backward compatibility only and may be confusing for others as it only applies to markers and not to other options.

minversion

Specifies a minimal pytest version required for running tests.

# content of pytest.ini
[pytest]
minversion = 3.0  # will fail if we run with pytest-2.8
norecursedirs

Set the directory basename patterns to avoid when recursing for test discovery. The individual (fnmatch-style) patterns are applied to the basename of a directory to decide if to recurse into it. Pattern matching characters:

*       matches everything
?       matches any single character
[seq]   matches any character in seq
[!seq]  matches any char not in seq

Default patterns are '*.egg', '.*', '_darcs', 'build', 'CVS', 'dist', 'node_modules', 'venv', '{arch}'. Setting a norecursedirs replaces the default. Here is an example of how to avoid certain directories:

[pytest]
norecursedirs = .svn _build tmp*

This would tell pytest to not look into typical subversion or sphinx-build directories or into any tmp prefixed directory.

Additionally, pytest will attempt to intelligently identify and ignore a virtualenv by the presence of an activation script. Any directory deemed to be the root of a virtual environment will not be considered during test collection unless ‑‑collect‑in‑virtualenv is given. Note also that norecursedirs takes precedence over ‑‑collect‑in‑virtualenv; e.g. if you intend to run tests in a virtualenv with a base directory that matches '.*' you must override norecursedirs in addition to using the ‑‑collect‑in‑virtualenv flag.

python_classes

One or more name prefixes or glob-style patterns determining which classes are considered for test collection. Search for multiple glob patterns by adding a space between patterns. By default, pytest will consider any class prefixed with Test as a test collection. Here is an example of how to collect tests from classes that end in Suite:

[pytest]
python_classes = *Suite

Note that unittest.TestCase derived classes are always collected regardless of this option, as unittest’s own collection framework is used to collect those tests.

python_files

One or more Glob-style file patterns determining which python files are considered as test modules. Search for multiple glob patterns by adding a space between patterns:

[pytest]
python_files = test_*.py check_*.py example_*.py

Or one per line:

[pytest]
python_files =
    test_*.py
    check_*.py
    example_*.py

By default, files matching test_*.py and *_test.py will be considered test modules.

python_functions

One or more name prefixes or glob-patterns determining which test functions and methods are considered tests. Search for multiple glob patterns by adding a space between patterns. By default, pytest will consider any function prefixed with test as a test. Here is an example of how to collect test functions and methods that end in _test:

[pytest]
python_functions = *_test

Note that this has no effect on methods that live on a unittest.TestCase derived class, as unittest’s own collection framework is used to collect those tests.

See Changing naming conventions for more detailed examples.

pythonpath

Sets list of directories that should be added to the python search path. Directories will be added to the head of sys.path. Similar to the PYTHONPATH environment variable, the directories will be included in where Python will look for imported modules. Paths are relative to the rootdir directory. Directories remain in path for the duration of the test session.

[pytest]
pythonpath = src1 src2
required_plugins

A space separated list of plugins that must be present for pytest to run. Plugins can be listed with or without version specifiers directly following their name. Whitespace between different version specifiers is not allowed. If any one of the plugins is not found, emit an error.

[pytest]
required_plugins = pytest-django>=3.0.0,<4.0.0 pytest-html pytest-xdist>=1.0.0
testpaths

Sets list of directories that should be searched for tests when no specific directories, files or test ids are given in the command line when executing pytest from the rootdir directory. Useful when all project tests are in a known location to speed up test collection and to avoid picking up undesired tests by accident.

[pytest]
testpaths = testing doc

This tells pytest to only look for tests in testing and doc directories when executing from the root directory.

usefixtures

List of fixtures that will be applied to all test functions; this is semantically the same to apply the @pytest.mark.usefixtures marker to all test functions.

[pytest]
usefixtures =
    clean_db
xfail_strict

If set to True, tests marked with @pytest.mark.xfail that actually succeed will by default fail the test suite. For more information, see strict parameter.

[pytest]
xfail_strict = True

Command-line Flags

All the command-line flags can be obtained by running pytest --help:

$ pytest --help
usage: pytest [options] [file_or_dir] [file_or_dir] [...]

positional arguments:
  file_or_dir

general:
  -k EXPRESSION         only run tests which match the given substring
                        expression. An expression is a python evaluatable
                        expression where all names are substring-matched
                        against test names and their parent classes.
                        Example: -k 'test_method or test_other' matches all
                        test functions and classes whose name contains
                        'test_method' or 'test_other', while -k 'not
                        test_method' matches those that don't contain
                        'test_method' in their names. -k 'not test_method
                        and not test_other' will eliminate the matches.
                        Additionally keywords are matched to classes and
                        functions containing extra names in their
                        'extra_keyword_matches' set, as well as functions
                        which have names assigned directly to them. The
                        matching is case-insensitive.
  -m MARKEXPR           only run tests matching given mark expression.
                        For example: -m 'mark1 and not mark2'.
  --markers             show markers (builtin, plugin and per-project ones).
  -x, --exitfirst       exit instantly on first error or failed test.
  --fixtures, --funcargs
                        show available fixtures, sorted by plugin appearance
                        (fixtures with leading '_' are only shown with '-v')
  --fixtures-per-test   show fixtures per test
  --pdb                 start the interactive Python debugger on errors or
                        KeyboardInterrupt.
  --pdbcls=modulename:classname
                        specify a custom interactive Python debugger for use
                        with --pdb.For example:
                        --pdbcls=IPython.terminal.debugger:TerminalPdb
  --trace               Immediately break when running each test.
  --capture=method      per-test capturing method: one of fd|sys|no|tee-sys.
  -s                    shortcut for --capture=no.
  --runxfail            report the results of xfail tests as if they were
                        not marked
  --lf, --last-failed   rerun only the tests that failed at the last run (or
                        all if none failed)
  --ff, --failed-first  run all tests, but run the last failures first.
                        This may re-order tests and thus lead to repeated
                        fixture setup/teardown.
  --nf, --new-first     run tests from new files first, then the rest of the
                        tests sorted by file mtime
  --cache-show=[CACHESHOW]
                        show cache contents, don't perform collection or
                        tests. Optional argument: glob (default: '*').
  --cache-clear         remove all cache contents at start of test run.
  --lfnf={all,none}, --last-failed-no-failures={all,none}
                        which tests to run with no previously (known)
                        failures.
  --sw, --stepwise      exit on test failure and continue from last failing
                        test next time
  --sw-skip, --stepwise-skip
                        ignore the first failing test but stop on the next
                        failing test.
                        implicitly enables --stepwise.

reporting:
  --durations=N         show N slowest setup/test durations (N=0 for all).
  --durations-min=N     Minimal duration in seconds for inclusion in slowest
                        list. Default 0.005
  -v, --verbose         increase verbosity.
  --no-header           disable header
  --no-summary          disable summary
  -q, --quiet           decrease verbosity.
  --verbosity=VERBOSE   set verbosity. Default is 0.
  -r chars              show extra test summary info as specified by chars:
                        (f)ailed, (E)rror, (s)kipped, (x)failed, (X)passed,
                        (p)assed, (P)assed with output, (a)ll except passed
                        (p/P), or (A)ll. (w)arnings are enabled by default
                        (see --disable-warnings), 'N' can be used to reset
                        the list. (default: 'fE').
  --disable-warnings, --disable-pytest-warnings
                        disable warnings summary
  -l, --showlocals      show locals in tracebacks (disabled by default).
  --tb=style            traceback print mode
                        (auto/long/short/line/native/no).
  --show-capture={no,stdout,stderr,log,all}
                        Controls how captured stdout/stderr/log is shown on
                        failed tests. Default is 'all'.
  --full-trace          don't cut any tracebacks (default is to cut).
  --color=color         color terminal output (yes/no/auto).
  --code-highlight={yes,no}
                        Whether code should be highlighted (only if --color
                        is also enabled)
  --pastebin=mode       send failed|all info to bpaste.net pastebin service.
  --junit-xml=path      create junit-xml style report file at given path.
  --junit-prefix=str    prepend prefix to classnames in junit-xml output

pytest-warnings:
  -W PYTHONWARNINGS, --pythonwarnings=PYTHONWARNINGS
                        set which warnings to report, see -W option of
                        python itself.
  --maxfail=num         exit after first num failures or errors.
  --strict-config       any warnings encountered while parsing the `pytest`
                        section of the configuration file raise errors.
  --strict-markers      markers not registered in the `markers` section of
                        the configuration file raise errors.
  --strict              (deprecated) alias to --strict-markers.
  -c file               load configuration from `file` instead of trying to
                        locate one of the implicit configuration files.
  --continue-on-collection-errors
                        Force test execution even if collection errors
                        occur.
  --rootdir=ROOTDIR     Define root directory for tests. Can be relative
                        path: 'root_dir', './root_dir',
                        'root_dir/another_dir/'; absolute path:
                        '/home/user/root_dir'; path with variables:
                        '$HOME/root_dir'.

collection:
  --collect-only, --co  only collect tests, don't execute them.
  --pyargs              try to interpret all arguments as python packages.
  --ignore=path         ignore path during collection (multi-allowed).
  --ignore-glob=path    ignore path pattern during collection (multi-
                        allowed).
  --deselect=nodeid_prefix
                        deselect item (via node id prefix) during collection
                        (multi-allowed).
  --confcutdir=dir      only load conftest.py's relative to specified dir.
  --noconftest          Don't load any conftest.py files.
  --keep-duplicates     Keep duplicate tests.
  --collect-in-virtualenv
                        Don't ignore tests in a local virtualenv directory
  --import-mode={prepend,append,importlib}
                        prepend/append to sys.path when importing test
                        modules and conftest files, default is to prepend.
  --doctest-modules     run doctests in all .py modules
  --doctest-report={none,cdiff,ndiff,udiff,only_first_failure}
                        choose another output format for diffs on doctest
                        failure
  --doctest-glob=pat    doctests file matching pattern, default: test*.txt
  --doctest-ignore-import-errors
                        ignore doctest ImportErrors
  --doctest-continue-on-failure
                        for a given doctest, continue to run after the first
                        failure

test session debugging and configuration:
  --basetemp=dir        base temporary directory for this test run.(warning:
                        this directory is removed if it exists)
  -V, --version         display pytest version and information about
                        plugins. When given twice, also display information
                        about plugins.
  -h, --help            show help message and configuration info
  -p name               early-load given plugin module name or entry point
                        (multi-allowed).
                        To avoid loading of plugins, use the `no:` prefix,
                        e.g. `no:doctest`.
  --trace-config        trace considerations of conftest.py files.
  --debug=[DEBUG_FILE_NAME]
                        store internal tracing debug information in this log
                        file.
                        This file is opened with 'w' and truncated as a
                        result, care advised.
                        Defaults to 'pytestdebug.log'.
  -o OVERRIDE_INI, --override-ini=OVERRIDE_INI
                        override ini option with "option=value" style, e.g.
                        `-o xfail_strict=True -o cache_dir=cache`.
  --assert=MODE         Control assertion debugging tools.
                        'plain' performs no assertion debugging.
                        'rewrite' (the default) rewrites assert statements
                        in test modules on import to provide assert
                        expression information.
  --setup-only          only setup fixtures, do not execute tests.
  --setup-show          show setup of fixtures while executing tests.
  --setup-plan          show what fixtures and tests would be executed but
                        don't execute anything.

logging:
  --log-level=LEVEL     level of messages to catch/display.
                        Not set by default, so it depends on the root/parent
                        log handler's effective level, where it is "WARNING"
                        by default.
  --log-format=LOG_FORMAT
                        log format as used by the logging module.
  --log-date-format=LOG_DATE_FORMAT
                        log date format as used by the logging module.
  --log-cli-level=LOG_CLI_LEVEL
                        cli logging level.
  --log-cli-format=LOG_CLI_FORMAT
                        log format as used by the logging module.
  --log-cli-date-format=LOG_CLI_DATE_FORMAT
                        log date format as used by the logging module.
  --log-file=LOG_FILE   path to a file when logging will be written to.
  --log-file-level=LOG_FILE_LEVEL
                        log file logging level.
  --log-file-format=LOG_FILE_FORMAT
                        log format as used by the logging module.
  --log-file-date-format=LOG_FILE_DATE_FORMAT
                        log date format as used by the logging module.
  --log-auto-indent=LOG_AUTO_INDENT
                        Auto-indent multiline messages passed to the logging
                        module. Accepts true|on, false|off or an integer.

[pytest] ini-options in the first pytest.ini|tox.ini|setup.cfg file found:

  markers (linelist):   markers for test functions
  empty_parameter_set_mark (string):
                        default marker for empty parametersets
  norecursedirs (args): directory patterns to avoid for recursion
  testpaths (args):     directories to search for tests when no files or
                        directories are given in the command line.
  filterwarnings (linelist):
                        Each line specifies a pattern for
                        warnings.filterwarnings. Processed after
                        -W/--pythonwarnings.
  usefixtures (args):   list of default fixtures to be used with this
                        project
  python_files (args):  glob-style file patterns for Python test module
                        discovery
  python_classes (args):
                        prefixes or glob names for Python test class
                        discovery
  python_functions (args):
                        prefixes or glob names for Python test function and
                        method discovery
  disable_test_id_escaping_and_forfeit_all_rights_to_community_support (bool):
                        disable string escape non-ascii characters, might
                        cause unwanted side effects(use at your own risk)
  console_output_style (string):
                        console output: "classic", or with additional
                        progress information ("progress" (percentage) |
                        "count").
  xfail_strict (bool):  default for the strict parameter of xfail markers
                        when not given explicitly (default: False)
  enable_assertion_pass_hook (bool):
                        Enables the pytest_assertion_pass hook.Make sure to
                        delete any previously generated pyc cache files.
  junit_suite_name (string):
                        Test suite name for JUnit report
  junit_logging (string):
                        Write captured log messages to JUnit report: one of
                        no|log|system-out|system-err|out-err|all
  junit_log_passing_tests (bool):
                        Capture log information for passing tests to JUnit
                        report:
  junit_duration_report (string):
                        Duration time to report: one of total|call
  junit_family (string):
                        Emit XML for schema: one of legacy|xunit1|xunit2
  doctest_optionflags (args):
                        option flags for doctests
  doctest_encoding (string):
                        encoding used for doctest files
  cache_dir (string):   cache directory path.
  log_level (string):   default value for --log-level
  log_format (string):  default value for --log-format
  log_date_format (string):
                        default value for --log-date-format
  log_cli (bool):       enable log display during test run (also known as
                        "live logging").
  log_cli_level (string):
                        default value for --log-cli-level
  log_cli_format (string):
                        default value for --log-cli-format
  log_cli_date_format (string):
                        default value for --log-cli-date-format
  log_file (string):    default value for --log-file
  log_file_level (string):
                        default value for --log-file-level
  log_file_format (string):
                        default value for --log-file-format
  log_file_date_format (string):
                        default value for --log-file-date-format
  log_auto_indent (string):
                        default value for --log-auto-indent
  pythonpath (paths):   Add paths to sys.path
  faulthandler_timeout (string):
                        Dump the traceback of all threads if a test takes
                        more than TIMEOUT seconds to finish.
  addopts (args):       extra command line options
  minversion (string):  minimally required pytest version
  required_plugins (args):
                        plugins that must be present for pytest to run

environment variables:
  PYTEST_ADDOPTS           extra command line options
  PYTEST_PLUGINS           comma-separated plugins to load during startup
  PYTEST_DISABLE_PLUGIN_AUTOLOAD set to disable plugin auto-loading
  PYTEST_DEBUG             set to enable debug tracing of pytest's internals


to see available markers type: pytest --markers
to see available fixtures type: pytest --fixtures
(shown according to specified file_or_dir or current dir if not specified; fixtures with leading '_' are only shown with the '-v' option