All you need to do is open the Terminal application and type python to get started (type ctrl+d to exit Python). Learn Python the Hard Way has everything you need to start programming in Python.

Python 3 introduced the idea of "type annotations," and as of Python 3.6, you can annotate variables, not just function parameters and return values. The idea is that you can put a colon (:) and then ...

An example of how simple community projects can have an outsized impact on Python are Type Hints, a Python 3.5 feature that was inspired by the mypy project launched by a PhD student back in 2012.