Naughty Python

2021-11-28: This is no longer true with Python 3

Here’s an interesting fact:

$ python --version
Python 2.7.2+
$ python --version | sed "s/7/2/"
Python 2.7.2+
$ python --version 2>&amp;1 | sed "s/7/2/"
Python 2.2.2+

Why CPython prints its version number on stderr? It’s worth remembering if you want for example control Python version in installer scripts.