If you write code that you'll use in a few programs, then you can put it into a "module." You can share that module with others -- and they can share their modules with you, too. In this lesson, we talk about modules , including how we can use them, how we can write simple modules of our own, and how we can download/retrieve modules from PyPI, the Python Package Index.
To download the Jupyter notebook I created when teaching this lesson, sign up (for free) at https://PythonForNonProgrammers.com .