command line arguments python

def arg_process():
    for arg in sys.argv[1:]:
       if arg in ["-h", "--help"]:
           print("usage:csv2html.py [maxwidth=int] [format=str] < infile.csv > outfile.html")
            return None, None
       elif arg.startswith(maxwidth_arg):
           try:
               maxwidth = int(arg[len(maxwidth_arg):])
           except ValueError:
               pass
       elif arg.startswith(format_arg):
           format = arg[len(format_arg):]
   return maxwidth, format