This section describes a classic and popular way how you can implement fixtures (setup and teardown test state) on a per-module/class/function basis. pytest started supporting these methods around 2005 and subsequently nose and the standard library introduced them (under slightly different names). While these setup/teardown methods are and will remain fully supported you may also use pytest’s more powerful fixture mechanism which leverages the concept of dependency injection, allowing for a more modular and more scalable approach for managing test state, especially for larger projects and for functional testing. You can mix both fixture mechanisms in the same file but unittest-based test methods cannot receive fixture arguments.
As of pytest-2.4, teardownX functions are not called if setupX existed and failed/was skipped. This harmonizes behaviour across all major python testing tools.
If you have multiple test functions and test classes in a single module you can optionally implement the following fixture methods which will usually be called once for all the functions:
def setup_module(module): """ setup any state specific to the execution of the given module.""" def teardown_module(module): """ teardown any state that was previously setup with a setup_module method. """
Similarly, the following methods are called at class level before and after all test methods of the class are called:
@classmethod def setup_class(cls): """ setup any state specific to the execution of the given class (which usually contains tests). """ @classmethod def teardown_class(cls): """ teardown any state that was previously setup with a call to setup_class. """
Similarly, the following methods are called around each method invocation:
def setup_method(self, method): """ setup any state tied to the execution of the given method in a class. setup_method is invoked for every test method of a class. """ def teardown_method(self, method): """ teardown any state that was previously setup with a setup_method call. """
If you would rather define test functions directly at module level you can also use the following functions to implement fixtures:
def setup_function(function): """ setup any state tied to the execution of the given function. Invoked for every test function in the module. """ def teardown_function(function): """ teardown any state that was previously setup with a setup_function call. """
Note that it is possible for setup/teardown pairs to be invoked multiple times per testing process.