code: def main(argv=None):
      
      if argv is None:
          argv = sys.argv
  
      parser = OptionParser()
  
      parser.add_option('-v', '--verbose', dest="verbose", action="count",
          default=2, help="be chattier (stackable)")
      def quiet(option, opt_str, value, parser):
          parser.values.verbose -= 1
      parser.add_option('-q', '--quiet', action="callback", callback=quiet,
          help="be less chatty (stackable)")
  
      parser.add_option('-r', action="store_true", dest="real_path",
          default=False, help="dereference symlinks")
      parser.add_option('-b', action="store_true", dest="show_directory",
          default=False, help="show directory instead of filename")
      parser.add_option('-i', '--hide-init', action="store_true", dest="hide_init",
          default=False, help="show directory if the module ends in __init__.py")
      parser.add_option('-s', '--source', action="store_true", dest="find_source",
          default=False, help="find .py files for .pyc/.pyo files")
      parser.add_option('--ver', action="store_true", dest="find_version",
          default=False, help="find the version of the named package, not the location on disk")
  
      opts, args = parser.parse_args()
  
      verbose = max(0, min(4, opts.verbose))
      log_levels = (logging.CRITICAL, logging.ERROR, logging.WARNING, logging.INFO, logging.DEBUG)
      logging.basicConfig()
      log.setLevel(log_levels[verbose])
  
      if opts.find_version:
          find_version(*args)
      else:
          kwargs = dict((fld, getattr(opts, fld)) for fld
              in ('real_path', 'show_directory', 'find_source', 'hide_init'))
          identify_modules(*args, **kwargs)
  
      return 0
docs: Run the pywhich command as if invoked with arguments `argv`.
  
      If `argv` is `None`, arguments from `sys.argv` are used.