count in python string

1string.count(substring, start, end)
2# Start and end is optional

1#printing the number of characters in  a string
2print(len("String you want to count"))
3
4#counting characters in a variable
5a = "some string"
6print(len(a))

1string.count(substring, start=..., end=...)
2
3'recede'.count('e')
4>>> 3
5'recede'.count('e', 2, 4)
6>>> 1

1def count_substring(string,sub_string):
2    l=len(sub_string)
3    count=0
4    for i in range(len(string)-len(sub_string)+1):
5        if(string[i:i+len(sub_string)] == sub_string ):      
6            count+=1
7    return count  
8