find all index of character in string python code example

Example 1: python3 return a list of indexes of a specific character in a string

string='mississippi'
s='s'
lst= []
for i in range(len(string)):
    if (string[i] == s):
        lst.append(i)
print(lst)
#result: [2, 3, 5, 6]

Example 2: how to find the indexes of a substring in a string in python

import re
# matches_position_start will be a list of starting index positions
matches_start = re.finditer(word.lower(), string.lower())
matches_position_start = [match.start() for match in matches_start]

# matches_position_end will be a list of ending index positions
matches_end = re.finditer(word.lower(), string.lower())
matches_position_end = [match.end() for match in matches_end]