Check to see if two lists have the same value at the same index, if so return the index. If not return -1

So basically I am trying to compare two lists to see if they hold the same value at the same index at any point. If they do I return the index, if they do not, I return -1.
`

Dlist = [17,13,10,6,2]
Ilist = [5,9,10,15,18]
def seqsearch(DS,IS):
    
    for i in range(len(DS)-1):
        found = False
        if DS[i] == IS[i]:
            answer = i
            found = True
            if found == True:
                print(f"Yes! Found at index =", answer)
            else:
                return print("No!\n-1")


print(seqsearch(Dlist,Ilist))

`

When I had first done this as a test I was having no issues however adding in the text has made it more difficult and my main issue is with the if else statement. I seem to be able to only get one message to work, either yes or no, not both based on the case.

>Solution :

You could loop over both lists like so:

Dlist = [17, 13, 10, 6, 2]
Ilist = [5, 9, 10, 15, 18]


def seqsearch(DS, IS):

    for index_1, element_1 in enumerate(DS):
        for index_2, element_2 in enumerate(IS):

            if (element_1 == element_2) and (index_1 == index_2):
                print(f"Yes! Found at index ={index_1}")
                return index_1
    print("No!")
    return -1


print(seqsearch(Dlist, Ilist))

However, there are more improvements you can make. zip() indeed is a better option, but slightly more complicated to understand.

Also, please note that return is not the same as print. You were not returning -1; you were printing it.