Why does this piece of code have this edge case

I was trying to try a palindrome test but a specific number 10022201, always returns true.

class Solution():
    def isPalindrome(x):
        if isinstance(x, int):
            x = str(x)
        for y in x:
            index = x.index(y)
            rev = x[::-1]
            if x[index] != rev[index]:
                b = bool(0)
                break
            else:
                b = bool(1)
        return b                
x = 10022201
solution = Solution()
result = Solution.isPalindrome(x)
print(result)

help please!

When you run x.index(y), it returns the first value in x that matches y. Therefore, when you're on the second zero, it returns the index of the first zero.

What you can do instead is this:

class Solution():
    def isPalindrome(x):
        if isinstance(x, int):
            x = str(x)
        for index in range(len(x)):
            rev = x[::-1]
            if x[index] != rev[index]:
                b = bool(0)
                break
            else:
                b = bool(1)
        return b   

Here, you go through all the possible indeces in the string, and then you check if each corresponding character is equivalent. Basically what you were trying to do, just simplified.

Also, you can just check for string equality, comparing the string of the number to the reversed version of that:

class Solution():
    def isPalindrome(x):
        if isinstance(x, int):
            x = str(x)
        rev = x[::-1] 
        return x == rev