• 高级super实例


      1 class CommandParser(ArgumentParser):
      2     """
      3     Customized ArgumentParser class to improve some error messages and prevent
      4     SystemExit in several occasions, as SystemExit is unacceptable when a
      5     command is called programmatically.
      6     """
      7     def __init__(self, cmd, **kwargs):
      8         self.cmd = cmd
      9         super(CommandParser, self).__init__(**kwargs)
     10 
     11     def parse_args(self, args=None, namespace=None):
     12         # Catch missing argument for a better error message
     13         if (hasattr(self.cmd, 'missing_args_message') and
     14                 not (args or any(not arg.startswith('-') for arg in args))):
     15             self.error(self.cmd.missing_args_message)
     16         return super(CommandParser, self).parse_args(args, namespace)
     17 
     18 class ArgumentParser(_AttributeHolder, _ActionsContainer):
     19     """Object for parsing command line strings into Python objects.
     20 
     21     Keyword Arguments:
     22         - prog -- The name of the program (default: sys.argv[0])
     23         - usage -- A usage message (default: auto-generated from arguments)
     24         - description -- A description of what the program does
     25         - epilog -- Text following the argument descriptions
     26         - parents -- Parsers whose arguments should be copied into this one
     27         - formatter_class -- HelpFormatter class for printing help messages
     28         - prefix_chars -- Characters that prefix optional arguments
     29         - fromfile_prefix_chars -- Characters that prefix files containing
     30             additional arguments
     31         - argument_default -- The default value for all arguments
     32         - conflict_handler -- String indicating how to handle conflicts
     33         - add_help -- Add a -h/-help option
     34         - allow_abbrev -- Allow long options to be abbreviated unambiguously
     35     """
     36 
     37     def __init__(self,
     38                  prog=None,
     39                  usage=None,
     40                  description=None,
     41                  epilog=None,
     42                  parents=[],
     43                  formatter_class=HelpFormatter,
     44                  prefix_chars='-',
     45                  fromfile_prefix_chars=None,
     46                  argument_default=None,
     47                  conflict_handler='error',
     48                  add_help=True,
     49                  allow_abbrev=True):
     50 
     51         superinit = super(ArgumentParser, self).__init__
     52         superinit(description=description,
     53                   prefix_chars=prefix_chars,
     54                   argument_default=argument_default,
     55                   conflict_handler=conflict_handler)
     56 
     57 
     58         # default setting for prog
     59         if prog is None:
     60             prog = _os.path.basename(_sys.argv[0])
     61 
     62         self.prog = prog
     63         self.usage = usage
     64         self.epilog = epilog
     65         self.formatter_class = formatter_class
     66         self.fromfile_prefix_chars = fromfile_prefix_chars
     67         self.add_help = add_help
     68         self.allow_abbrev = allow_abbrev
     69 
     70         add_group = self.add_argument_group
     71         self._positionals = add_group(_('positional arguments'))
     72         self._optionals = add_group(_('optional arguments'))
     73         self._subparsers = None
     74 
     75         # register types
     76         def identity(string):
     77             return string
     78         self.register('type', None, identity)
     79 
     80         # add help argument if necessary
     81         # (using explicit default to override global argument_default) 显式覆盖全局
     82         default_prefix = '-' if '-' in prefix_chars else prefix_chars[0]
     83         if self.add_help:
     84             self.add_argument(
     85                 default_prefix+'h', default_prefix*2+'help',
     86                 action='help', default=SUPPRESS,
     87                 help=_('show this help message and exit'))
     88 
     89         # add parent arguments and defaults
     90         for parent in parents:
     91             self._add_container_actions(parent)
     92             try:
     93                 defaults = parent._defaults
     94             except AttributeError:
     95                 pass
     96             else:
     97                 self._defaults.update(defaults)
     98 
     99         def parse_args(self, args=None, namespace=None):
    100         args, argv = self.parse_known_args(args, namespace)
    101         if argv:
    102             msg = _('unrecognized arguments: %s')
    103             self.error(msg % ' '.join(argv))
    104         return args
  • 相关阅读:
    你的项目中使用过哪些JSTL标签?
    web资源的运行原理
    Java与Andriod的区别和关系
    request.getAttribute()和 request.getParameter()有何区别?
    groupId和artifactId
    MySQL锁(一)全局锁:如何做全库的逻辑备份?
    SPRINGBOOT集成SWAGGER2
    RabbitMQ 消息中间件(三)
    RabbitMQ 消息中间件(二)
    RabbitMQ 消息中间件(一)
  • 原文地址:https://www.cnblogs.com/Fmaj7/p/13180289.html
Copyright © 2020-2023  润新知