How and why does PyCharm alter Python's import logic?

Question

I have a PyCharm 1.2.1 on Windows. I have to edit different branches of the same project - somewhat heavy branches, because they live in different folders on disk - say it to be

Answer 1

The correct solution is not to try to work around PyCharm's logic, but rather to use the IDE features as they're designed. That means:

• Not use any .cmd scripts for starting up PyCharm
• Remove all the paths specific to "alpha" and "beta" from the list of paths in Settings | Python Interpreters if any are listed there
• Mark the "alpha/vendor" and "beta/vendor" directories as source roots in the alpha and beta projects respectively.

Then PyCharm will resolve imports correctly and generate the correct PYTHONPATH automatically when running the application from it.