import string
import math

# def isPalindrome(s):
#     """
#     :type s: str
#     :rtype: bool
#     """
    # # Create a translation table to remove uppercase letters and special characters
    # # translation_table = str.maketrans("","", string.punctuation + string.whitespace)
    # translation_table = ''.join(c.lower() if c.isupper() or c.isalnum() else '' for c in s if c.isalnum() or c in string.whitespace)
    # # print(translation_table)
    # if len(translation_table) == 2:
    #     if translation_table[0] == translation_table[1]:
    #         return True
    #     else:
    #         return False

    # # Use the translation table to remove uppercase letters and special characters
    # # upper_string = s.translate(translation_table)
    # # lower_string = upper_string.lower()
    # lower_string = translation_table

    # half = len(lower_string)/2
    # # Round the value down since middle value doesn't matter
    # if len(lower_string)%2 != 0:
    #     halfdown = int(math.floor(half))
    # else:
    #     halfdown = int(half)
    # # print(halfup)
    # # print(halfdown)
    # first = []
    # second = []
    # print(lower_string)

    # for i in range(halfdown):
    #     # print(i)
    #     # print(lower_string[i])
    #     first.append(lower_string[i])

    # if len(lower_string)%2 != 0:
    #     for j in range(halfdown+1, len(lower_string)):
    #         second.insert(0, lower_string[j])

    # else:
    #     for j in range(halfdown, len(lower_string)):
    #         second.insert(0, lower_string[j])

    # print(first)
    # print(second)
    # if first == second:
    #     return True
    # else:
    #     return False

#Fastest solution
# Operator ~ is the bitwise NOT operator (~x == -x-1 => ~0 == -1 => ~1 == -2 and etc), 
# which expects just one argument. It performs logical negation on a given number by 
# flipping all of its bits:
def isPalindrome(s: str) -> bool:
    s = [c.lower() for c in s if c.isalnum()]
    return all (s[i] == s[~i] for i in range(len(s)//2))

print(isPalindrome("A man, a plan, a canal: Panama"))
print(isPalindrome("aa"))
print(isPalindrome("0P"))
print(isPalindrome("abba"))