Source Code for Module ivs.aux.argkwargparser

 1  """ 
 2  Automatically parse command line args and kwargs. 
 3   
 4  This module is meant to facilitate the translation of command line arguments to 
 5  Python code to parse to methods. 
 6   
 7  Example usage: 
 8   
 9  Given an example minimalistic Python module 'example.py' 
10   
11  >>> def testfunc(a,b,calc='sum'): 
12  >>> ... if calc=='sum': return a+b 
13  >>> ... elif calc=='prod': return a*b 
14  >>> ... return None 
15   
16  >>> if __name__=="__main__": 
17  >>> ... method,args,kwargs = argkwargparser.parse() 
18  >>> ... output = globals()[method](*args,**kwargs) 
19   
20  Then, in a terminal, you can do:: 
21   
22      $:> python example.py testfunc 3 4 
23      7 
24      $:> python example.py testfunc 3 4 calc=prod 
25      12 
26   
27  You can mix args and kwargs, they will be sorted by L{parse}. You can give lists 
28  and more sophisticated input for args and kwargs, see L{parse}. 
29   
30  """ 
31  import json 
32  import sys 
33       
34 -def parse(argv=None): 
35      """ 
36      Command-line to method call arg processing. 
37       
38          - positional args: a b -> method('a', 'b') 
39          - intifying args: a 123 -> method('a', 123) 
40          - json loading args: a '["pi", 3.14, null]' -> method('a', ['pi', 3.14, None]) 
41          - keyword args: a foo=bar -> method('a', foo='bar') 
42          - using more of the above 1234 'extras=["r2"]'  -> method(1234, extras=["r2"]) 
43       
44      @param argv: Command line arg list. Defaults to `sys.argv`. 
45      @return: method-name, args, kwargs 
46      @rtype: string, list, dict 
47      """ 
48      if argv is None: 
49          argv = sys.argv 
50   
51      method_name, arg_strs = argv[1], argv[2:] 
52      args = [] 
53      kwargs = {} 
54      for s in arg_strs: 
55          #-- keyword argument if '=' in string 
56          if s.count('=') == 1: 
57              key, value = s.split('=', 1) 
58              #-- maybe the user preceded the keyword with '--' out of habit. In 
59              #   that case remove it 
60              if key[:2]=='--': 
61                  key = key[2:] 
62          #-- normal argument 
63          else: 
64              key, value = None, s 
65          try: 
66              value = json.loads(value)  
67          except ValueError: 
68              pass 
69          if key: 
70              kwargs[key] = value 
71          else: 
72              args.append(value) 
73      return method_name, args, kwargs 
74   
75 -def test(*args,**kwargs): 
76      print 'args',args 
77      print 'kwargs',kwargs 
78   
79  if __name__=="__main__": 
80      method,args,kwargs = parse() 
81      out = globals()[method](*args, **kwargs) 
82      sys.exit(out) 
83