Updated Python One-Line Player

#!/usr/bin/env python
#
#   Examples:
#
#   Linux (-d plays immediately via /dev/dsp):
#   python playit.py -d '(t>>7|t|t>>6)*10+4*(t&t>>13|t>>6)'
#
#   WAV compatible OS (-w writes to file):
#   python playit.py -w -o output.wav '(t>>7|t|t>>6)*10+4*(t&t>>13|t>>6)'
#

import sys, optparse, wave

parser = optparse.OptionParser(
    usage='%prog [options] t-expr',
    description='''
    Based on "Experimental one-line algorithmic music":
    http://countercomplex.blogspot.com/2011/10/algorithmic-symphonies-from-one-line-of.html
    ''')
parser.set_defaults(outfile=None, start=0, length=30, wrapper=None)
parser.add_option('-s', '--start', dest='start',
                  type='int', help='Set starting position in seconds')
parser.add_option('-l', '--length', dest='length',
                  type='int', help='Set length in seconds')
parser.add_option('-d', '--dsp', dest='outfile', action='store_const',
                  const='/dev/dsp', help='Send to /dev/dsp audio output')
parser.add_option('-w', '--wave', dest='wrapper', action='store_const',
                  const='wav', help='Add a WAV wrapper')
parser.add_option('-o', '--output', dest='outfile', action='store',
                  help='Send output to specified file instead of stdout')
opts, args = parser.parse_args()

if len(args) != 1:
    parser.print_help()
    sys.exit(20)
t_expr, = args

outfile = opts.outfile
if outfile:
    output = open(outfile, 'wb')
else:
    output = sys.stdout
wrapper = opts.wrapper
if wrapper == 'wav':
    output = wave.open(output)
    output.setnchannels(1)
    output.setsampwidth(1)
    output.setframerate(8000)
    writer = output.writeframes
else:
    writer = output.write
start = opts.start
length = opts.length

t_start = 8000 * int(start)
t_end = t_start + 8000 * int(length)
stream = eval(
    '("".join(chr(int(%s) & 0xFF) for t in xrange(s, s + 8000)) '
                                 ' for s in xrange(%d, %d, 8000))'
    % (t_expr, t_start, t_end))
for chunk in stream:
    writer(chunk)