Ya'll answers are complicated. I still used it for reference and this is what I came up with.

def count_substring(string, sub_string): counter = 0

for i in range(1, len(string)):
    if sub_string in string:
        find = string.find(sub_string)
        string = string[find + 1:]
        counter += 1
return counter

if name == 'main': string = input().strip() sub_string = input().strip()

count = count_substring(string, sub_string)
print(count)