pytest.main() capture standard output

问题

I have a method I am using to get all of the tests we have.

def get_test_names_from_file():

    get_test_names = pytest.main(['--collect-only', '-q'])
    print(type(get_test_names))

    return 'here is the methods return: ' + str(get_test_names)

When I call this method it returns an exist code here is the methods return: 0 and that's fine. What I can not figure out is how I get the resulting standard out into a format that I can use.

Here is the standard out when the method is called:

test_a.py::TestA::test_general_a
test_a.py::TestA::test_python_a
test_a.py::TestA::test_python_learning_a
test_b.py::TestB::test_b

How do I capture this output so that I can return it? I have done my best to read through the docs, and can't seem to figure out a way to do this.

Thank you for your time.

EDIT: I was able to get something working using subprocess, but i'd prefer to use pytest rather than mix and match:

def get_test_names_from_file():

    pytest_command_string = 'pytest --collect-only -q'
    pytest_command = subprocess.Popen(pytest_command_string.split(), shell=False, stdout=subprocess.PIPE)
    pytest_command_out = pytest_command.communicate()[0]

    print(type(pytest_command_out))
    return pytest_command_out

回答1:

You could use py.io for this.

something like:

capture = py.io.StdCapture()
pytest.main(['--collect-only', '-q'])
std, err = capture.reset()
print(std)

Would get you the standard output you're looking for.

来源：https://stackoverflow.com/questions/50763003/pytest-main-capture-standard-output