(question) Cleaning up from parameter generation

[beaumitch]

Hi, I'm wondering what the best practices are for cleaning up after a function that generates parameters for an @parametrize .
Here's a minimal example of what I'd like to accomplish:

import pytest

def get_test_files():
    data_directory = generate_data_directory()
    for filename in data_directory:
        yield filename
    delete_data_directory()

@pytest.mark.parametrize("filename", get_test_files())
def test_file(filename):
    with open('./data/' + filename, 'rb') as test_file:
        assert my_module.process_file(test_file) == expected_result

But delete_data_directory runs during collection, before test time. So instead, I'm looking at using a hack like this:

import pytest

def get_test_files():
    global data_directory
    data_directory = generate_data_directory()
    for filename in data_directory:
        yield filename

@pytest.fixture(scope="session")
def teardown():
    yield None
    delete_data_directory(data_directory)

@pytest.mark.parametrize("filename", get_test_files())
def test_file(filename, teardown):
    with open('./data/' + filename, 'rb') as test_file:
        assert my_module.process_file(test_file) == expected_result

What's the right way to accomplish something like this?

edit: The 'autouse' argument makes this much cleaner; I'll just go with this.

import pytest

def get_test_files():
    global data_directory
    data_directory = generate_data_directory()
    for filename in data_directory:
        yield filename

@pytest.fixture(scope="session", autouse=True)
def teardown():
    yield
    delete_data_directory(data_directory)

@pytest.mark.parametrize("filename", get_test_files())
def test_file(filename):
    with open('./data/' + filename, 'rb') as test_file:
        assert my_module.process_file(test_file) == expected_result

[pytestbot]

GitMate.io thinks possibly related issues are #1120 (Cleaning up tmpdir's), #2272 (Question: Can callable as argument to ids parameter of parametrize of operate on a tuple?), #543 (Should tmpdir clean up after itself?), #1748 (deprecate unpacking marks in parameter values and provide a clean alternative), and #1843 (Parameter corruption for parameterized tests).