how to count the sub strings in python code example

Example 1: count substring in string python

#When we need to split and then perform match
import re
re.split("\W", sentence.lower())

Example 2: count substring in string python

def count_substring(string,sub_string):
    l=len(sub_string)
    count=0
    for i in range(len(string)-len(sub_string)+1):
        if(string[i:i+len(sub_string)] == sub_string ):      
            count+=1
    return count