I am in a project where we are starting refactoring some massive code base. One problem that immediately sprang up is that each file imports a lot of other files. How do I in an elegant way mock this in my unit test without having to alter the actual code so I can start to write unit-tests?
As an example: The file with the functions I want to test, imports ten other files which is part of our software and not python core libs.
I want to be able to run the unit tests as separately as possible and for now I am only going to test functions that does not depend on things from the files that are being imported.
EDIT
Thanks for all the answers.
I didn't really know what I wanted to do from the start but now I think I know.
Problem was that some imports was only possible when the whole application was running because of some third-party auto-magic. So I had to make some stubs for these modules in a directory which I pointed out with sys.path
Now I can import the file which contains the functions I want to write tests for in my unit-test file without complaints about missing modules.