computing the steps in a diatonic scale

#! /usr/local/bin/python

# takes one argument: an integer representing the position in
# the set of keys (beginning with 'A')

# takes one argument: an integer representing the position in
# the set of keys (beginning with 'A')

# key   number
# A         0
# Bb    1
# B         2
# C     3
# C#    4
# D     5
# Eb    6
# E     7
# F     8
# F#    9
# G    10
# Ab   11

import sys

# the key the user requested on the command line
requested_key = int(sys.argv[1])

# the set of keys (equivalent to the chromatic scale)
# (two octaves used to make the script simpler)

key_set = ('A', 'Bb', 'B', 'C', 'C#', 'D', 'Eb', 'E', 'F', 'F#', 'G', 'Ab', 'A', 'Bb', 'B', 'C', 'C#', 'D', 'Eb', 'E', 'F', 'F#', 'G', 'Ab')

# the intervals (the spacing) in the diatonic scale
# (interval = number of steps in the chromatic scale from one step to another step)

diatonic_scale_intervals_set = (2, 2, 1, 2, 2, 2, 1)

cur_key_set_position = requested_key

print key_set[cur_key_set_position],

for interval in diatonic_scale_intervals_set:
    cur_key_set_position = cur_key_set_position + interval
    print '%s ' % key_set[cur_key_set_position],