Not only CPython
The main Python implementation is written in the C language and is called CPython. It is the one that the majority of people refer to when they talk about Python. When the language evolves, the C implementation is changed accordingly. Besides C, Python is available in a few other implementations that are trying to keep up with the mainstream. Most of them are a few milestones behind CPython, but provide a great opportunity to use and promote the language in a specific environment.
Why should I care?
There are plenty of alternative Python implementations available. The Python Wiki page on that topic (https://wiki.python.org/moin/PythonImplementations) features more than 20 different language variants, dialects, or implementations ...
Get Expert Python Programming - Second Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.