https://stackoverflow.com/questions/24955896/pycharm-indexing-goes-into-infinite-loop
I opened up a directory with PyCharm, and after it was done indexing, I still didn't get code completion suggestions, so I invalidated the cache. When I reopened PyCharm, I noticed that it was indexing
/usr/local/google_appengine/google_appengine/google_appengine/...
so it turns out there's a symlink or alias (not sure which) to itself. So I removed it, invalidated the cache and restarted PyCharm. When PyCharm started, the same problem was back, so it looks like PyCharm put the symlink back. How do I tell pycnarm to use the file system as its source of information?
Open up
Preferences > Project Settings > Project Structure
Select the symlink and exlcude it from the project. This will prevent Pycharm from including and indexing the folder.