Python command line hex-byte viewer

hex.py

#!/usr/bin/env python

import os
from argparse import ArgumentParser

parser = ArgumentParser()
parser.add_argument("file",   help="which file to view in hex format")
parser.add_argument("-f", "--head", help="if given, show only the first n*16 bytes", type=int)
parser.add_argument("-t", "--tail", help="if given, show only the last n*16 bytes", type=int)
parser.add_argument("-s", "--split", help="if given, show n bytes per line", type=int, default=16)

args = parser.parse_args()

with open(args.file, 'rb') as file:
    contents = file.read()

if args.head:
    contents = contents[0: (args.head) * args.split]
elif args.tail:
    contents = contents[len(contents) - args.tail * args.split:]

size = len(contents)
print("Showing %d bytes:\n" % size)
for i in range(size):
    print(hex(contents[i])[2:].zfill(2).upper(), end=' ' if i % args.split != args.split - 1 else '\n')