In PyCharm, open the Preferences/Settings window, then go to Project > Project Interpreter. You should see a screen that looks like this:
On the bottom, click on the plus (+) sign, then search for your Python package. For this set of instructions, we will use the
networkx package. The description should read "Python package for creating and manipulating graphs and networks".
Click "Install Package"; once it says "Package 'networkx' installed successfully", close both windows.