Est-ce que Plaindrome Python

def is_palindrome(s):
      	#check if it's a string
    if type(s) != str:
        raise ValueError("This is not a string")
    #return list of capital letters ignore other characters such as (, ! ? ...)
    l1 = list(map(lambda x : x.isalpha and x.upper(), s))
    #remove False from list 
    l1 = [x for x in l1 if x != False]
    #reverse the previous list 
    l2 = list(reversed(l1))
    # check is l1 equal to l2 ?
    return l1 == l2


print(is_palindrome(input("Enter a string ")))
Mero