Solution Exercise 56: python program that find the first index of given occurrence within a given string

Exercise 56

Write a python program as a function which takes as parameter a tuple of string (s, s1) and which returns the index of the first occurrence of s1 found within the string s. The function must returns -1 if s1 is not found within the string s. Example if s = "Python Programming" and s1 = "thon" , the function returns the index 2

Solution

def Find(s , s1):
    n = len(s)
    m = len(s1)
    k = -1
    for i in range(0 , n):
        if s[i:i+m] == s1:
            k = i
            break
    return k

s = "Python Programming" 
s1 = "thon"
print(Find(s , s1))      # display 2
print(Find(s , 'thons')) # display -1