What is the difference between mocks and stubs in Python testing?

What is the difference between mocks and stubs in Python testing?

Mocks and stubs are both used in testing to isolate components, but they serve different purposes. A stub is a simple implementation that returns predefined responses, while a mock is a more complex object that can verify interactions.

Can you give me an example of when to use a mock instead of a stub?

Sure! Use a mock when you want to verify that a function was called with specific arguments, like checking if a database query was executed correctly. A stub would be used when you just need to provide a fixed response without caring about how it was called.

Are there any libraries in Python that help with mocking and stubbing?

Yes, the unittest.mock library is built into Python and provides tools for creating mocks and stubs. You can also use third-party libraries like pytest-mock for more advanced features.

What are some best practices for using mocks and stubs?

Some best practices include keeping your tests simple, using mocks only when necessary, and ensuring that your tests remain readable and maintainable.