12days.py

# Python 2

lister = ['extra-input to cover the 0',
 'A Partridge in a Pear Tree.',
 '2 Turtle Doves',
 '3 French Hens',
 '4 Colly Birds',
 '5 Golden Rings',
 '6 Geese-a-Laying',
 '7 Swans-a-Swimming',
 '8 Maids-a-Milking',
 '9 Ladies Dancing',
 '10 Lords-a-Leaping',
 '11 Pipers Piping',
 '12 Drummers Drumming']

nth = ['th', 'st', 'nd', 'rd']

# Recursively print individual verses
def verse (n):
    if 1 <= n <= 12:
        print lister[n]
        if n == 2: print "And",
        verse(n - 1)

# Recursively print the carol from the starting verse
def carol (n):
    if 1 <= n <= 12:
        print "On the %d%s day of Christmas, my true love gave to me..." % (
          n, nth[n if n < 4 else 0])
        verse(n)
        print ""
        carol(n - 1)

what_verse = int(raw_input('What verse (1-12) do you want? '))
carol(what_verse)