Categorise integration tests using PyTest.

conftest.py

import pytest


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


def pytest_runtest_setup(item):
    if 'integration' in item.keywords:
        item.config.getoption("--integration", skip=True)

test_test.py

import pytest


def test_unit_test():
    assert True
    

@pytest.mark.integration
def test_integration_test():
    assert True

Using pytest 3.0.3 the conftest.py provided failed for me throwing a ValueError.
This is what worked for me.

import pytest

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


def pytest_runtest_setup(item):
    if 'integration' in item.keywords:
        item.config.getoption("--integration", skip=True)

That's great, thanks for the share @tasosval

This is what I ended up with, the logic could be very different depending on the use case:

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


def pytest_runtest_setup(item):
    """
    Only run tests marked with 'integration' when --integration is passed
    """
    run_integration = item.config.getoption("--integration")

    if run_integration and 'integration' not in item.keywords:
        pytest.skip("skipping test not marked as integration")
    elif 'integration' in item.keywords and not run_integration:
        pytest.skip("pass --integration option to pytest to run this test")