Print rearranged page counts to reflect the order of the pages when printed as booklets of 3, double sided, sheets

booklet_page_counter.py

# Booklet of counter of sheets
booklet_sheet_count = 3
booklet_package_page_count = booklet_sheet_count * 2 * 2

pages = sys.argv[1:]
if len(pages) % booklet_package_page_count != 0:
	sys.stderr.write("Page count of PDF needs to be a multiple of " + str(booklet_run_count) + ".\n")
	sys.stderr.write("You can append blank pages using Preview if needed. Select the last page and choose 'Edit > Insert > Blank Page'.\n")
	sys.exit(1)

page_count = len(pages)
run_count = len(pages) / booklet_package_page_count

sys.stdout.write("Number of pages = " + str(page_count) + "\n")
sys.stdout.write("Pages per sheet = " + str(2) + "\n")
sys.stdout.write("Sheet count per run = " + str(booklet_sheet_count) + "\n")
sys.stdout.write("Pages per run = " + str(booklet_package_page_count) + "\n")
sys.stdout.write("Runs = " + str(run_count) + "\n")

for i in range(0, page_count, booklet_package_page_count):
	start = i
	end = i + booklet_package_page_count-1
	
	double_page_counter = 2 * booklet_sheet_count
	
	for n in range(0, double_page_counter):
		if n % 2 == 0:
			print(pages[end])
			print(pages[start])
		else:
			print(pages[start])
			print(pages[end])
		
		start += 1
		end -= 1
		
		pass
	pass

# usage:
# python test.py 1 2 3 4 5 6 7 8 9 10 11 12

/* output */
12
1
2
11
10
3
4
9
8
5
6
7