caesar cipher

#!/usr/bin/env python

import sys,string

def caesar(plaintext, shift):
    alphabet = string.ascii_lowercase
    shifted_alphabet = alphabet[shift:] + alphabet[:shift]
    table = str.maketrans(alphabet, shifted_alphabet)
    return plaintext.translate(table)

source = input("Please input your text: ")
shift = input("Please input shift: ")
print(caesar(source, int(shift)))