Stripping everything but alphanumeric chars from a string in Python

Question

What is the best way to strip all non alphanumeric characters from a string, using Python?

The solutions presented in the PHP variant of this question will probably

Answer 1

Regular expressions to the rescue:

import re
re.sub(r'\W+', '', your_string)

By Python definition '\W == [^a-zA-Z0-9_], which excludes all numbers, letters and _