PyPI = Python Package Index
Python is great because of it's vast collection of libraries and packages.
You can find almost all of them here at PyPI
This is Python's official repository. Here you can browse for specific packages, even check out different categories.
Generally packages have their own dedicated page that lists versions, updates, how to install and other info.
Project venv + pip
Here is where it all comes together.
Let's say you want to install certain packages/libraries for your project.
Confirm that you venv is activated and use the
pip
command to install what you need.
If you were building a web application and needed a light weight framework, one could install Flask.
pip install flask
Or if you need a library for machine learning:
pip install scikit-learn
These are just a few examples.
When you download these libraries via pip, it will download the latest version available on PyPI and install it in your Python environment.
So the project is isolated with the virtual environment and all dependencies within.