Caesar's Cipher (v.1)

caesar_cipher_1

#!/bin/python

import sys


n = int(raw_input().strip())
s = raw_input().strip()
k = int(raw_input().strip())


def shift_n_letters(letter, n):
    shift_amount = n % 26
    raw_ord = ord(letter) + shift_amount

    # ...for no loop-arounds, straightforward cases
    if ((ord(letter) >= ord('A') and ord(letter) <= ord('Z')) and (raw_ord >= ord('A') and raw_ord <= ord('Z'))) or ((ord(letter) >= ord('a') and ord(letter) <= ord('z')) and (raw_ord >= ord('a') and raw_ord <= ord('z'))):
        return chr(raw_ord)

    # Lower-case extended shift
    elif (ord(letter) >= ord('a') and ord(letter) <= ord('z')):
        loop_amt = shift_amount - (ord('z') - ord(letter))
        return chr(ord('a') + loop_amt - 1)

    # Upper-case extended shift
    elif (ord(letter) >= ord('A') and ord(letter) <= ord('Z')):
        loop_amt = shift_amount - (ord('Z') - ord(letter))
        return chr(ord('A') + loop_amt - 1)


def rotate(text, n):
    output = ''
    for letter in text:
        if ord(letter) in list(range(ord('a'), ord('z') + 1)) or ord(letter) in list(range(ord('A'), ord('Z') + 1)):
            output += shift_n_letters(letter, n)
        else:
            output += letter
    return output

print rotate(s, k)

Note: HackerRank 30 Days of Code: Day 4