python check palindrome fast way

import sys

arg = sys.argv[1]
arg_length = len(sys.argv[1])

print("arg_length: ",arg_length)

def palindrome(arg, arg_length):
    for i in range(0,int(arg_length/2)): # for checking half string
        if arg[i] != arg[arg_length-i-1]:
            return False
    return True

print(palindrome(arg, arg_length))

Output:

[home@fedora ~]$ python3 palidrom.py 11211
arg_length:  5
True
[home@fedora ~]$ python3 palidrom.py noon
arg_length:  4
True
[home@fedora ~]$ python3 palidrom.py qwerty
arg_length:  6
False