Bryce Beagle

If it looks like a duck and quacks like a duck, it must be a duck. The `unittest.mock` stdlib provides a powerful mocking framework for unit tests with dynamic, ephemeral patching—but how does it work behind the scenes?

You've typed `import x` or `from y import z` in your Python programs countless times. But you probably don't know what really goes on behind the scenes. When are import statements actually evaluated? How does Python know where to find packages? What does importing a package even do at runtime?