This problem has plagued me for months now. One day, PyCharm boots up my app fine. The next it gives the following error:

Traceback (most recent call last):
  File "/Applications/PyCharm.app/Contents/helpers/pydev/pydevd.py", line 2, in
    from __future__ import nested_scopes # Jython 2.1 support
ImportError: No module named __future__

The only fix I've been able to find is:

1. Close out of your current project, as well as PyCharm completely.
2. Completely remove the .idea/ folder contained within your project's root directory
3. Open PyCharm and now recreate your project.

This is a super annoying bug that I can't find the answer to. Please let me know if you come across a better fix than what I've outlined above.