Why do we need environment variables?

Suppose that you have a FastAPI app that lives in a Python file. This app might be self contained, but it might still need to access a database and that means that we need a way to pass a password to the app at the start of a program.

The main reason for this is that we don't want to hardcode the password in the Python file. If we do that, we might accidentally share the password with others. This is a security risk. The solution is to use environment variables and this course will highlight how to use them in Python.