CPython

CPython is the reference and official implementation of the Python programming language. Written in C, it’s the most widely used version of Python and serves as the standard upon which other implementations are based.

When you download Python from the official website, python.org, you’re getting CPython. This implementation is known for its performance and compatibility with various C libraries, making it a popular choice for many Python developers.

Example

Once you install Python from the python.org website, you can run the python command on a terminal window. Then, you’ll get something like the following on your screen:

Python 
Python 3.12.2 (main, Mar 10 2024, 19:25:46)...
Type "help", "copyright", "credits" or "license" for more information.
>>>

This is a Python REPL (Read-Eval-Print Loop) session where you can run Python code interactively. You can check the Python implementation you’re using by running the following code:

Python 
>>> import platform
>>> platform.python_implementation()
'CPython'

In this code, you call the python_implementation() function from the platform module to check the Python implementation in use.