pytest: print fixture output after test runs

conftest.py

import pytest

@pytest.mark.hookwrapper
def pytest_pyfunc_call(pyfuncitem):
    yield
    print('pyfunc call after')
    if 'watch_logs' in pyfuncitem.funcargs:
        print(pyfuncitem.funcargs['watch_logs']())


@pytest.fixture
def watch_logs(request):
    with open('/tmp/mylogs.txt') as f:
        log_before = f.read()

    def get_new_logs():
        with open('/tmp/mylogs.txt') as f:
            log_after = f.read()
        return log_after.replace(log_before, '')

    return get_new_logs

tests.py

from thing import do_stuff

def test_doing_stuff_passes(watch_logs):
    print('in test, should pass')
    assert do_stuff() == 42

def test_doing_stuff_fails(watch_logs):
    print('in test, should fail')
    assert do_stuff() == 43

thing.py

import time

def do_stuff():
    with open('/tmp/mylogs.txt', 'a') as f:
        f.write('ran at {}\n'.format(time.time()))
    return 42