find index of substring in string python code example

Example 1: python index of string

string = "Hello World"
string_slice = string[1:10] # "ello Worl" (index 1 up to 10)
string_last_chars = string[-5:] # "World" (5th index from last to the end)
H = string[0] # "H"

Example 2: python string indexof

s = "mouse"
animal_letter = s.find('s')
print animal_letter

Example 3: find in python

def find_all_indexes(input_str, search_str):
    l1 = []
    length = len(input_str)
    index = 0
    while index < length:
        i = input_str.find(search_str, index)
        if i == -1:
            return l1
        l1.append(i)
        index = i + 1
    return l1


s = 'abaacdaa12aa2'
print(find_all_indexes(s, 'a'))
print(find_all_indexes(s, 'aa'))

Example 4: python get index of substring in liast

def index_containing_substring(the_list, substring):
    for i, s in enumerate(the_list):
        if substring in s:
              return i
    return -1

Example 5: 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]