How to patch a module's internal functions with mock?

Question

By \"internal function\", I mean a function that is called from within the same module it is defined in.

I am using the mock library, specifically the patch decorators,

Answer 1

The answer: Clean up your darned imports

@patch('mymodule.TAX_LOCATION', '') did indeed patch things appropriately, but since our imports at the time were very haphazard -- sometimes we imported mymodule.build_cart, sometimes we imported project.mymodule.build_cart -- instances of the "full" import were not patched at all. Mock couldn't be expected to know about the two separate import paths... without being told explicitly, anyway.

We've since standardized all our imports on the longer path, and things behave much more nicely now.