pytest Command Line Option to include integration tests

You need to declare the custom marker, e.g. in pytest.ini:

# pytest.ini
[pytest]
markers = 
    integration: mark a test as integration

To maintain the --integration command line option some changes need to be done to the pytest plugin module conftest.py:

# conftest.py

def pytest_addoption(parser):
    parser.addoption("--integration", action="store_true",
                      help="run integration tests")

def pytest_runtest_setup(item):
    if 'integration' in item.keywords and not \
            item.config.getvalue("integration"):
        pytest.skip("need --integration option to run")

First function pytest_addoption is a pytest hook which is executed during command line options setup. The function adds the --integration command line option to pytest.

The second function pytest_runtest_setup is a pytest hook which is invoked during the setup for each test. If the test is marked with integration it will be skipped.

You could mark all tests from a python file as integration tests:

# test_something.py

# ... your code ...

pytestmark = pytest.mark.integration

# ... your code ...