count substring in string python

string.count(substring, start, end)
# Start and end is optional

# Python code to demonstrate  
# to count total number 
# of substring in string 
  
import re 
# Initialising string 
ini_str = "ababababa"
sub_str = 'aba'
  
# Count count of substrings using re.finditer 
res = sum(1 for _ in re.finditer('(?= aba)', ini_str)) 
  
# Printing result 
print("Number of substrings", res) 

string.count(substring, [start_index], [end_index])

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  

# using count() to get count  
# counting e  
counter = test_str.count('e')