When PyCharm stops supporting any on the outdated Python variations, the corresponding project interpreter is marked as unsupported. Once you’re applying external libraries (from PyPI or somewhere else), you'll want to handle the variations of those also. The Pythonic Alternative for this are virtualenvs (sometimes abbreviated to venv). Sometimes http://programminghomeworkhelp96161.amoblog.com/the-best-side-of-python-project-help-14075961