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pythonpytestparametrize

Pytest parametrize run after the last iteration


When using @pytest.mark.parametrize('arg', param) is there a way to find out if the last item in param is being run? The reason I'm asking is I want to run a cleanup function unique to that test that should only run after the very last iteration of param.

param = [(1, 'James'), (2, 'John')]
@pytest.mark.parametrize('id, user', param)
def test_myfunc(id, user):
    # Do something
    print(user)

    # Run this only after the last param which would be after (2, 'John')
    print('All done!')

I can run a conditional which checks for the value of param but I was just wondering if pytest has a way for this.


Solution

  • You'll need to perform this logic within a pytest hook, specifically the pytest_runtest_teardown hook.

    Assuming your test looks like the following,

    import pytest
    
    param = [(1, 'James'), (2, 'John')]
    @pytest.mark.parametrize('id, user', param)
    def test_myfunc(id, user):
        print(f"Iteration number {id}")
    

    In the root of your test folder, create a conftest.py file and place the following,

    func_of_interest = "test_myfunc"
    
    def pytest_runtest_teardown(item, nextitem):
        curr_name = item.function.__qualname__
        # check to see it is the function we want
        if curr_name == func_of_interest:
            # check to see if there are any more functions after this one
            if nextitem is not None:
                next_name = nextitem.function.__qualname__
            else:
                next_name = "random_name"
            # check to see if the next item is a different function
            if curr_name != next_name:
                print("\nPerform some teardown once")
    

    Then when we run it, it produces the following output,

    ===================================== test session starts ======================================
    platform darwin -- Python 3.9.1, pytest-6.2.2, py-1.10.0, pluggy-0.13.1
    cachedir: .pytest_cache
    rootdir: ***
    collected 2 items                                                                              
    
    test_grab.py::test_myfunc[1-James] Iteration number 1
    PASSED
    test_grab.py::test_myfunc[2-John] Iteration number 2
    PASSED
    Perform some teardown once
    

    As we can see, the teardown logic was called exactly once, after the final iteration of the test call.