Escaping regex string

Question

I want to use input from a user as a regex pattern for a search over some text. It works, but how I can handle cases where user puts characters that have meaning in regex?<

Answer 1

You can use re.escape():

re.escape(string) Return string with all non-alphanumerics backslashed; this is useful if you want to match an arbitrary literal string that may have regular expression metacharacters in it.

>>> import re
>>> re.escape('^a.*$')
'\\^a\\.\\*\\$'

If you are using a Python version < 3.7, this will escape non-alphanumerics that are not part of regular expression syntax as well.

If you are using a Python version < 3.7 but >= 3.3, this will escape non-alphanumerics that are not part of regular expression syntax, except for specifically underscore (_).