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Find all the indexes of all the occurrences of a word in a string in Python

Last Updated : April 27, 2025

To retrieve the index of all the occurrences of a word in the string (say a statement), Python, like most of the programming languages supports the regular expression module as a built-in module. Or if we don't want the overhead of using the regular expressions, we could also use the str.index() in an iteration to get the index and also using the comprehension.

Find All Indexes of Word Occurrences in a String Using Regular Expression Module

The below example, explains the usage of the regex module's (re) method finditer() which takes the 'word' or substring to be searched for and the sentence in which the 'word' shall be searched, as the argument.

The output of the below example is the start index and end index of the word 'to' in the sentence.

Example

# importing the module
import re

# sentence and word to be found
sentence = "This is a sample sentence to search for include help to search all occurrences"
word = "to"

# logic
for match in re.finditer(word, sentence):
    print("match found from {} to {}".format(match.start(), match.end()))

Output

match found from 26 to 28
match found from 53 to 55

Find All Indexes of Word Occurrences in a String Using str.index()

The following code demonstrates how to find all occurrences of a word in a sentence using the str.find() method.

def using_str_index (word, sentence):
    index = 0;
    while index < len(sentence):
        index = sentence.find(word, index)
        if index == -1:
            break
        print('{} found at {}'.format(word, index))
        index += len(word)

if __name__ == '__main__':    
    sentence = "This is a sample sentence to search for include help to search all occurrences"
    word = "to"
    using_str_index(word, sentence)

Output

to found at 26
to found at 53

Find All Indexes of Word Occurrences in a String Using Comprehension

This code uses list comprehension to find and print all starting indices of a word in a sentence.

Example

def using_comprehension(word, sentence):
    print([n for n in range(len(sentence)) if sentence.find(word, n) == n])

if __name__== "__main__":
    sentence = "This is a sample sentence to search for include help to search all occurrences"
    word = "to"
    using_comprehension(word, sentence)

Output

[26, 53]

Exercise

Select the correct option to complete each statement about finding all the indexes of all occurrences of a word in a string in Python.

1. To find all the indexes of occurrences of a word in a string, you can use the ___ method of the string object. --Select-- find index finditer
2. To get all the occurrences, you can use the ___ function from the re module in Python. --Select-- findall search match
3. To get the index of each occurrence, the findall method from re returns a ___ of matched results. --Select-- list tuple dict