Python Testing Best Practices

Writing tests is essential for maintaining code quality. Python has excellent testing tools including pytest, unittest, and coverage.py.

Pytest is the most popular testing framework for Python. It offers simple syntax, powerful fixtures, and rich plugin ecosystem.

Key principles for effective testing:

1. Test behavior, not implementation
2. Use factories instead of fixtures for test data
3. Keep tests independent — no shared state
4. Aim for 80%+ code coverage on new code
5. Use mocking sparingly — prefer integration tests

For Django projects, pytest-django provides fixtures like 'client', 'admin_client', and database access markers that simplify testing Django views and models.