regex - How to match any string from a list of strings in regular expressions in python?

Question

Lets say I have a list of strings,

string_lst = ['fun', 'dum', 'sun', 'gum']

I want to make a regular expression, where at a point in it, I can match any of the strings i have in that list, within a group, such as this:

import re
template = re.compile(r".*(elem for elem in string_lst).*")
template.match("I love to have fun.")

What would be the correct way to do this? Or would one have to make multiple regular expressions and match them all separately to the string?

Answer 1

Join the list on the pipe character |, which represents different options in regex.

string_lst = ['fun', 'dum', 'sun', 'gum']
x="I love to have fun."

print re.findall(r"(?=("+'|'.join(string_lst)+r"))", x)

Output: ['fun']

You cannot use match as it will match from start. Using search you will get only the first match. So use findall instead.

Also use lookahead if you have overlapping matches not starting at the same point.