Duplex printing aid for non-duplex printers

duplex_print_range.py

#!/usr/bin/env python3

# Duplex printing aid for non-duplex printers
#
# This tool splits page ranges into odd and even page numbers.
# Print the first set in one go, feed the paper back and print the second set.

import os
import sys

if len(sys.argv) == 1:
	print("Enter page ranges, separated by commas or spaces.")
	sys.exit(0)

pages = set()
for page_range in ",".join(sys.argv[1:]).split(","):
	if "-" in page_range:
		start, end = [int(x) for x in page_range.split("-")]
		for page in range(start, end + 1):
			pages.add(page)
	else:
		pages.add(int(page_range))

pages = list(pages)
pages.sort()

split = [[], []] # even, odds
for page in pages:
	split[(page % 2)].append(str(page))

if (pages[0] % 2) == 1:
	split.reverse()

print(",".join(split[0]))
print(",".join(split[1]))