Option parsing refactoring ; Moved version string to __version__

Brings terser option formatting to youtube-dl:
  from: -u USERNAME, --username USERNAME
  to:   -u, --username USERNAME

youtube-dl

@@ -12,6 +12,7 @@ __author__  = (
 	)
 
 __license__ = "Public Domain"
+__version__ = '2011.08.04'
 
 import cookielib
 import ctypes
@@ -2725,59 +2726,80 @@ def updateSelf(downloader, filename):
 	downloader.to_screen('Updated to version %s' % latest_version)
 
 
-if __name__ == '__main__':
+def parseOpts():
-	try:
+	# Deferred imports
-		# Modules needed only when running the main program
 	import getpass
 	import optparse
 
+	def _format_option_string(option):
+		''' ('-o', '--option') -> -o, --format METAVAR'''
 
-		# Parse command line
+		opts = []
-		parser = optparse.OptionParser(
+
-			usage='Usage: %prog [options] url...',
+		if option._short_opts: opts.append(option._short_opts[0])
-			version='2011.08.04',
+		if option._long_opts: opts.append(option._long_opts[0])
-			conflict_handler='resolve',
+		if len(opts) > 1: opts.insert(1, ', ')
-		)
+
+		if option.takes_value(): opts.append(' %s' % option.metavar)
+
+		return "".join(opts)
+
+	fmt = optparse.IndentedHelpFormatter()
+	fmt.format_option_strings = _format_option_string
+
+	kw = {
+		'version'   : __version__,
+		'formatter' : fmt,
+		'usage' : 'Usage : %prog [options] url...',
+		'conflict_handler' : 'resolve',
+	}
+
+	parser = optparse.OptionParser(**kw)
 
-		parser.add_option('-h', '--help',
+	# option groups
+	general        = optparse.OptionGroup(parser, 'General Options')
+	authentication = optparse.OptionGroup(parser, 'Authentication Options')
+	video_format   = optparse.OptionGroup(parser, 'Video Format Options')
+	postproc       = optparse.OptionGroup(parser, 'Post-processing Options')
+	filesystem     = optparse.OptionGroup(parser, 'Filesystem Options')
+	verbosity      = optparse.OptionGroup(parser, 'Verbosity / Simulation Options')
+
+	general.add_option('-h', '--help',
 			action='help', help='print this help text and exit')
-		parser.add_option('-v', '--version',
+	general.add_option('-v', '--version',
 			action='version', help='print program version and exit')
-		parser.add_option('-U', '--update',
+	general.add_option('-U', '--update',
 			action='store_true', dest='update_self', help='update this program to latest stable version')
-		parser.add_option('-i', '--ignore-errors',
+	general.add_option('-i', '--ignore-errors',
 			action='store_true', dest='ignoreerrors', help='continue on download errors', default=False)
-		parser.add_option('-r', '--rate-limit',
+	general.add_option('-r', '--rate-limit',
 			dest='ratelimit', metavar='LIMIT', help='download rate limit (e.g. 50k or 44.6m)')
-		parser.add_option('-R', '--retries',
+	general.add_option('-R', '--retries',
 			dest='retries', metavar='RETRIES', help='number of retries (default is 10)', default=10)
-		parser.add_option('--playlist-start',
+	general.add_option('--playlist-start',
 			dest='playliststart', metavar='NUMBER', help='playlist video to start at (default is 1)', default=1)
-		parser.add_option('--playlist-end',
+	general.add_option('--playlist-end',
 			dest='playlistend', metavar='NUMBER', help='playlist video to end at (default is last)', default=-1)
-		parser.add_option('--dump-user-agent',
+	general.add_option('--dump-user-agent',
 			action='store_true', dest='dump_user_agent',
 			help='display the current browser identification', default=False)
 
-		authentication = optparse.OptionGroup(parser, 'Authentication Options')
 	authentication.add_option('-u', '--username',
 			dest='username', metavar='USERNAME', help='account username')
 	authentication.add_option('-p', '--password',
 			dest='password', metavar='PASSWORD', help='account password')
 	authentication.add_option('-n', '--netrc',
 			action='store_true', dest='usenetrc', help='use .netrc authentication data', default=False)
-		parser.add_option_group(authentication)
 
-		video_format = optparse.OptionGroup(parser, 'Video Format Options')
+
 	video_format.add_option('-f', '--format',
 			action='store', dest='format', metavar='FORMAT', help='video format code')
 	video_format.add_option('--all-formats',
 			action='store_const', dest='format', help='download all available video formats', const='-1')
 	video_format.add_option('--max-quality',
 			action='store', dest='format_limit', metavar='FORMAT', help='highest quality format to download')
-		parser.add_option_group(video_format)
 
-		verbosity = optparse.OptionGroup(parser, 'Verbosity / Simulation Options')
+
 	verbosity.add_option('-q', '--quiet',
 			action='store_true', dest='quiet', help='activates quiet mode', default=False)
 	verbosity.add_option('-s', '--simulate',
@@ -2800,9 +2822,8 @@ if __name__ == '__main__':
 	verbosity.add_option('--console-title',
 			action='store_true', dest='consoletitle',
 			help='display progress in console titlebar', default=False)
-		parser.add_option_group(verbosity)
 
-		filesystem = optparse.OptionGroup(parser, 'Filesystem Options')
+
 	filesystem.add_option('-t', '--title',
 			action='store_true', dest='usetitle', help='use title in file name', default=False)
 	filesystem.add_option('-l', '--literal',
@@ -2825,16 +2846,29 @@ if __name__ == '__main__':
 	filesystem.add_option('--no-mtime',
 			action='store_false', dest='updatetime',
 			help='do not use the Last-modified header to set the file modification time', default=True)
-		parser.add_option_group(filesystem)
 
-		postproc = optparse.OptionGroup(parser, 'Post-processing Options')
+
 	postproc.add_option('--extract-audio', action='store_true', dest='extractaudio', default=False,
 			help='convert video files to audio-only files (requires ffmpeg and ffprobe)')
 	postproc.add_option('--audio-format', metavar='FORMAT', dest='audioformat', default='best',
 			help='"best", "aac" or "mp3"; best by default')
+
+
+	parser.add_option_group(general)
+	parser.add_option_group(filesystem)
+	parser.add_option_group(verbosity)
+	parser.add_option_group(video_format)
+	parser.add_option_group(authentication)
 	parser.add_option_group(postproc)
 
-		(opts, args) = parser.parse_args()
+	opts, args = parser.parse_args()
+
+	return parser, opts, args
+
+
+if __name__ == '__main__':
+	try:
+		parser, opts, args = parseOpts()
 
 		# Open appropriate CookieJar
 		if opts.cookiefile is None: