Let's say we'd like to see the documentation of this function. We can choose View | Quick Documentation for this (or its corresponding keyboard shortcut). You will see a pop-up window showing that documentation, as follows:
Viewing documentation in PyCharm
What's more, you can also view the documentation for your own functions (or methods, classes, and so on) using the same action since PyCharm scans through all code in its projects. Move your cursor to the call to prime_check() in the main scope in the following line (which should be around line 38):
if prime_check(num):
If you evoke the same Quick Documentation action, ...
