Python program to accept two strings and check if second string is prefix of first

str1 = input("enter the string")

str2 = input("enter the sub string")

flag =0

if len(str1) > len(str2):

    for i in range(0,len(str2)):

        #print(i)

        if str1[i] == str2[i]:

            pass

            #i=i+1

        flag=flag+1

        

print(str1,str2,end="\n")

print("matched at position{}".format(flag))

output:

enter the stringsubject

enter the sub stringsub

subject sub

matched at position3