How to count repeated substring in a given string in Python

By Aarushi Dwivedi

In this article, we will learn how to use the inbuilt count function using examples. Then we will see how to count repeated substring in a given string in Python.

Python has a built-in function for counting the repeated substring in a given string called count(). As the name suggests, it counts the occurrence of a substring in a given string.

Python – count() function

string="abcdefghijklmnop"
string.count(substring, start_index, end_index)

The count function has 3 parameters.

1. Substring: This parameter is compulsory since it specifies the string whose occurrence is to be found.
2. Start_index: This parameter is optional. It gives the starting index of the string from which the search will begin.
3. End_index: This parameter is optional. It gives the ending index of the string where the search for substring will end.

Read: Count number of occurrences of a substring in a string in Python

Count repeated substring in a given string in Python

1. This example only contains the compulsory parameter. In this, we first define a string, then by using the count function calculate the occurrence of substring “aab” in the string defined above.

   string= "aabbcaabcbbcaabdaab"
   print(string.count("aab"))

   Output:

   4

2. This example contains compulsory as well as the optional parameters. In this, we first define a string, then by using the count function calculate the occurrence of substring “aab” in the string starting from index 2 and ending at index 15 instead of considering the whole string.

   string= "aabbcaabcbbcaabdaab"
   print(string.count("aab",2,15))

   Output:

   2