# content of conftest.py import pytest def pytest_addoption(parser): parser.addoption( "--runslow", action="store_true", default=False, help="run slow tests" ) def pytest_collection_modifyitems(config, items): if config.getoption("--runslow"): # --runslow given in cli: do not skip slow tests return skip_slow = pytest.mark.skip(reason="need --runslow option to run") for item in items: if "slow" in item.keywords: item.add_marker(skip_slow)