argparse.ArgumentParser

实例化一个对象，默认参数一堆，只有description参数可以设置一下

parser=argparse.ArgumentParser(description="This is a example program ")

add_help：默认是True，可以设置False禁用

class ArgumentParser(_AttributeHolder, _ActionsContainer)

 |  Object for parsing command line strings into Python objects.

 |  

 |  Keyword Arguments:

 |      - prog -- The name of the program (default: sys.argv[0])

 |      - usage -- A usage message (default: auto-generated from arguments)

 |      - description -- A description of what the program does

 |      - epilog -- Text following the argument descriptions

 |      - parents -- Parsers whose arguments should be copied into this one

 |      - formatter_class -- HelpFormatter class for printing help messages

 |      - prefix_chars -- Characters that prefix optional arguments

 |      - fromfile_prefix_chars -- Characters that prefix files containing

 |          additional arguments

 |      - argument_default -- The default value for all arguments

 |      - conflict_handler -- String indicating how to handle conflicts

 |      - add_help -- Add a -h/-help option

 |      - allow_abbrev -- Allow long options to be abbreviated unambiguously

 |  Method resolution order:

 |      ArgumentParser

 |      _AttributeHolder

 |      _ActionsContainer

 |      builtins.object

 |  Methods defined here:

 |  __init__(self, prog=None, usage=None, description=None, epilog=None, parents=[], formatter_class=<class 'argparse.HelpFormatter'>, prefix_chars='-', fromfile_prefix_chars=None, argument_default=None, conflict_handler='error', add_help=True, allow_abbrev=True)

 |      Initialize self.  See help(type(self)) for accurate signature.

 |  add_subparsers(self, **kwargs)

 |      # ==================================

 |      # Optional/Positional adding methods

 |  convert_arg_line_to_args(self, arg_line)

 |  error(self, message)

 |      error(message: string)

 |      

 |      Prints a usage message incorporating the message to stderr and

 |      exits.

 |      If you override this in a subclass, it should not return -- it

 |      should either exit or raise an exception.

 |  exit(self, status=0, message=None)

 |      # ===============

 |      # Exiting methods

 |  format_help(self)

 |  format_usage(self)

 |      # =======================

 |      # Help-formatting methods

 |  parse_args(self, args=None, namespace=None)

 |      # =====================================

 |      # Command line argument parsing methods

 |  parse_known_args(self, args=None, namespace=None)

 |  print_help(self, file=None)

 |  print_usage(self, file=None)

 |      # =====================

 |      # Help-printing methods

 |  ----------------------------------------------------------------------

 |  Methods inherited from _AttributeHolder:

 |  __repr__(self)

 |      Return repr(self).

 |  Data descriptors inherited from _AttributeHolder:

 |  __dict__

 |      dictionary for instance variables (if defined)

 |  __weakref__

 |      list of weak references to the object (if defined)

 |  Methods inherited from _ActionsContainer:

 |  add_argument(self, *args, **kwargs)

 |      add_argument(dest, ..., name=value, ...)

 |      add_argument(option_string, option_string, ..., name=value, ...)

 |  add_argument_group(self, *args, **kwargs)

 |  add_mutually_exclusive_group(self, **kwargs)

 |  get_default(self, dest)

 |  register(self, registry_name, value, object)

 |      # ====================

 |      # Registration methods

 |  set_defaults(self, **kwargs)

 |      # Namespace default accessor methods