pseudo-python code to add a default subcommand

subcommand.py

--#!/usr/bin/python -tt # W: Missing module docstring    
      
  import argparse    
  import sys    
      
      
  global_options = argparse.ArgumentParser()    
  global_options.add_argument('--debug', action='store_true')    
  global_option_names = frozenset(('--debug', '-d', 'convert', 'analyze'))                                                                                               
                                                                                                                                                      
  common_options = argparse.ArgumentParser()                
  common_options.add_argument('--servurl')      
      
>>parser = argparse.ArgumentParser(parent=[global_options]) # E: Unexpected keyword argument 'parent' in constructor call    
      
  sub = parser.add_subparsers(required=True)    
>>analyze_options = sub.add_parser('analyze', parent=[global_options, common_options]) # E: line too long (84 > 79 characters)    
>>convert_options = sub.add_parser('convert', parent=[global_options, common_options]) # E: line too long (84 > 79 characters)    
      
  args = sys.argv[:]                                                                                                                                                                                             
  for index, arg in enumerate(args):    
      if arg not in global_option_names:    
          break    
                                                                                                                                                                                                                 
  if not ('convert' in args[:index] or 'analyze' in args[:index]):    
      args.insert(0, 'convert')    
                                                                                                                                                                                                                 
  parser.parse_args(args)