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

Answer 1

regex module has named lists (sets actually):

#!/usr/bin/env python
import regex as re # $ pip install regex

p = re.compile(r"\L", words=['fun', 'dum', 'sun', 'gum'])
if p.search("I love to have fun."):
    print('matched')

Here words is just a name, you can use anything you like instead.
.search() methods is used instead of .* before/after the named list.

To emulate named lists using stdlib's re module:

#!/usr/bin/env python
import re

words = ['fun', 'dum', 'sun', 'gum']
longest_first = sorted(words, key=len, reverse=True)
p = re.compile(r'(?:{})'.format('|'.join(map(re.escape, longest_first))))
if p.search("I love to have fun."):
    print('matched')

re.escape() is used to escape regex meta-characters such as .*? inside individual words (to match the words literally).
sorted() emulates regex behavior and it puts the longest words first among the alternatives, compare:

>>> import re
>>> re.findall("(funny|fun)", "it is funny")
['funny']
>>> re.findall("(fun|funny)", "it is funny")
['fun']
>>> import regex
>>> regex.findall(r"\L", "it is funny", words=['fun', 'funny'])
['funny']
>>> regex.findall(r"\L", "it is funny", words=['funny', 'fun'])
['funny']