--- /dev/null
+# -*- coding: utf-8 -*-
+
+# Copyright © 2006 Steven J. Bethard <steven.bethard@gmail.com>.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted under the terms of the 3-clause BSD
+# license. No warranty expressed or implied.
+# For details, see the accompanying file LICENSE.txt.
+
+"""Command-line parsing library
+
+This module is an optparse-inspired command-line parsing library that:
+
+* handles both optional and positional arguments
+* produces highly informative usage messages
+* supports parsers that dispatch to sub-parsers
+
+The following is a simple usage example that sums integers from the
+command-line and writes the result to a file:
+
+ parser = argparse.ArgumentParser(
+ description='sum the integers at the command line')
+ parser.add_argument(
+ 'integers', metavar='int', nargs='+', type=int,
+ help='an integer to be summed')
+ parser.add_argument(
+ '--log', default=sys.stdout, type=argparse.FileType('w'),
+ help='the file where the sum should be written')
+ args = parser.parse_args()
+ args.log.write('%s' % sum(args.integers))
+ args.log.close()
+
+The module contains the following public classes:
+
+ ArgumentParser -- The main entry point for command-line parsing. As the
+ example above shows, the add_argument() method is used to populate
+ the parser with actions for optional and positional arguments. Then
+ the parse_args() method is invoked to convert the args at the
+ command-line into an object with attributes.
+
+ ArgumentError -- The exception raised by ArgumentParser objects when
+ there are errors with the parser's actions. Errors raised while
+ parsing the command-line are caught by ArgumentParser and emitted
+ as command-line messages.
+
+ FileType -- A factory for defining types of files to be created. As the
+ example above shows, instances of FileType are typically passed as
+ the type= argument of add_argument() calls.
+
+ Action -- The base class for parser actions. Typically actions are
+ selected by passing strings like 'store_true' or 'append_const' to
+ the action= argument of add_argument(). However, for greater
+ customization of ArgumentParser actions, subclasses of Action may
+ be defined and passed as the action= argument.
+
+ HelpFormatter, RawDescriptionHelpFormatter -- Formatter classes which
+ may be passed as the formatter_class= argument to the
+ ArgumentParser constructor. HelpFormatter is the default, while
+ RawDescriptionHelpFormatter tells the parser not to perform any
+ line-wrapping on description text.
+
+All other classes in this module are considered implementation details.
+(Also note that HelpFormatter and RawDescriptionHelpFormatter are only
+considered public as object names -- the API of the formatter objects is
+still considered an implementation detail.)
+"""
+
+import os as _os
+import re as _re
+import sys as _sys
+import textwrap as _textwrap
+
+from gettext import gettext as _
+
+SUPPRESS = '==SUPPRESS=='
+
+OPTIONAL = '?'
+ZERO_OR_MORE = '*'
+ONE_OR_MORE = '+'
+PARSER = '==PARSER=='
+
+# =============================
+# Utility functions and classes
+# =============================
+
+class _AttributeHolder(object):
+ """Abstract base class that provides __repr__.
+
+ The __repr__ method returns a string in the format:
+ ClassName(attr=name, attr=name, ...)
+ The attributes are determined either by a class-level attribute,
+ '_kwarg_names', or by inspecting the instance __dict__.
+ """
+
+ def __repr__(self):
+ type_name = type(self).__name__
+ arg_strings = []
+ for arg in self._get_args():
+ arg_strings.append(repr(arg))
+ for name, value in self._get_kwargs():
+ arg_strings.append('%s=%r' % (name, value))
+ return '%s(%s)' % (type_name, ', '.join(arg_strings))
+
+ def _get_kwargs(self):
+ return sorted(self.__dict__.items())
+
+ def _get_args(self):
+ return []
+
+def _ensure_value(namespace, name, value):
+ if getattr(namespace, name, None) is None:
+ setattr(namespace, name, value)
+ return getattr(namespace, name)
+
+
+
+# ===============
+# Formatting Help
+# ===============
+
+class HelpFormatter(object):
+
+ def __init__(self,
+ prog,
+ indent_increment=2,
+ max_help_position=24,
+ width=None):
+
+ # default setting for width
+ if width is None:
+ try:
+ width = int(_os.environ['COLUMNS'])
+ except (KeyError, ValueError):
+ width = 80
+ width -= 2
+
+ self._prog = prog
+ self._indent_increment = indent_increment
+ self._max_help_position = max_help_position
+ self._width = width
+
+ self._current_indent = 0
+ self._level = 0
+ self._action_max_length = 0
+
+ self._root_section = self._Section(self, None)
+ self._current_section = self._root_section
+
+ self._whitespace_matcher = _re.compile(r'\s+')
+ self._long_break_matcher = _re.compile(r'\n\n\n+')
+
+ # ===============================
+ # Section and indentation methods
+ # ===============================
+
+ def _indent(self):
+ self._current_indent += self._indent_increment
+ self._level += 1
+
+ def _dedent(self):
+ self._current_indent -= self._indent_increment
+ assert self._current_indent >= 0, 'Indent decreased below 0.'
+ self._level -= 1
+
+ class _Section(object):
+ def __init__(self, formatter, parent, heading=None):
+ self.formatter = formatter
+ self.parent = parent
+ self.heading = heading
+ self.items = []
+
+ def format_help(self):
+ # format the indented section
+ if self.parent is not None:
+ self.formatter._indent()
+ join = self.formatter._join_parts
+ for func, args in self.items:
+ func(*args)
+ item_help = join(func(*args) for func, args in self.items)
+ if self.parent is not None:
+ self.formatter._dedent()
+
+ # return nothing if the section was empty
+ if not item_help:
+ return ''
+
+ # add the heading if the section was non-empty
+ if self.heading is not SUPPRESS and self.heading is not None:
+ current_indent = self.formatter._current_indent
+ heading = '%*s%s:\n' % (current_indent, '', self.heading)
+ else:
+ heading = ''
+
+ # join the section-initial newline, the heading and the help
+ return join(['\n', heading, item_help, '\n'])
+
+ def _add_item(self, func, args):
+ self._current_section.items.append((func, args))
+
+ # ========================
+ # Message building methods
+ # ========================
+
+ def start_section(self, heading):
+ self._indent()
+ section = self._Section(self, self._current_section, heading)
+ self._add_item(section.format_help, [])
+ self._current_section = section
+
+ def end_section(self):
+ self._current_section = self._current_section.parent
+ self._dedent()
+
+ def add_text(self, text):
+ if text is not SUPPRESS and text is not None:
+ self._add_item(self._format_text, [text])
+
+ def add_usage(self, usage, optionals, positionals, prefix=None):
+ if usage is not SUPPRESS:
+ args = usage, optionals, positionals, prefix
+ self._add_item(self._format_usage, args)
+
+ def add_argument(self, action):
+ if action.help is not SUPPRESS:
+
+ # update the maximum item length
+ invocation = self._format_action_invocation(action)
+ action_length = len(invocation) + self._current_indent
+ self._action_max_length = max(self._action_max_length,
+ action_length)
+
+ # add the item to the list
+ self._add_item(self._format_action, [action])
+
+ def add_arguments(self, actions):
+ for action in actions:
+ self.add_argument(action)
+
+ # =======================
+ # Help-formatting methods
+ # =======================
+
+ def format_help(self):
+ help = self._root_section.format_help() % dict(prog=self._prog)
+ if help:
+ help = self._long_break_matcher.sub('\n\n', help)
+ help = help.strip('\n') + '\n'
+ return help
+
+ def _join_parts(self, part_strings):
+ return ''.join(part
+ for part in part_strings
+ if part and part is not SUPPRESS)
+
+ def _format_usage(self, usage, optionals, positionals, prefix):
+ if prefix is None:
+ prefix = _('usage: ')
+
+ # if no optionals or positionals are available, usage is just prog
+ if usage is None and not optionals and not positionals:
+ usage = '%(prog)s'
+
+ # if optionals and positionals are available, calculate usage
+ elif usage is None:
+ usage = '%(prog)s' % dict(prog=self._prog)
+
+ # determine width of "usage: PROG" and width of text
+ prefix_width = len(prefix) + len(usage) + 1
+ prefix_indent = self._current_indent + prefix_width
+ text_width = self._width - self._current_indent
+
+ # put them on one line if they're short enough
+ format = self._format_actions_usage
+ action_usage = format(optionals + positionals)
+ if prefix_width + len(action_usage) + 1 < text_width:
+ usage = '%s %s' % (usage, action_usage)
+
+ # if they're long, wrap optionals and positionals individually
+ else:
+ optional_usage = format(optionals)
+ positional_usage = format(positionals)
+ indent = ' ' * prefix_indent
+
+ # usage is made of PROG, optionals and positionals
+ parts = [usage, ' ']
+
+ # options always get added right after PROG
+ if optional_usage:
+ parts.append(_textwrap.fill(
+ optional_usage, text_width,
+ initial_indent=indent,
+ subsequent_indent=indent).lstrip())
+
+ # if there were options, put arguments on the next line
+ # otherwise, start them right after PROG
+ if positional_usage:
+ part = _textwrap.fill(
+ positional_usage, text_width,
+ initial_indent=indent,
+ subsequent_indent=indent).lstrip()
+ if optional_usage:
+ part = '\n' + indent + part
+ parts.append(part)
+ usage = ''.join(parts)
+
+ # prefix with 'usage:'
+ return '%s%s\n\n' % (prefix, usage)
+
+ def _format_actions_usage(self, actions):
+ parts = []
+ for action in actions:
+ if action.help is SUPPRESS:
+ continue
+
+ # produce all arg strings
+ if not action.option_strings:
+ parts.append(self._format_args(action, action.dest))
+
+ # produce the first way to invoke the option in brackets
+ else:
+ option_string = action.option_strings[0]
+
+ # if the Optional doesn't take a value, format is:
+ # -s or --long
+ if action.nargs == 0:
+ part = '%s' % option_string
+
+ # if the Optional takes a value, format is:
+ # -s ARGS or --long ARGS
+ else:
+ default = action.dest.upper()
+ args_string = self._format_args(action, default)
+ part = '%s %s' % (option_string, args_string)
+
+ # make it look optional if it's not required
+ if not action.required:
+ part = '[%s]' % part
+ parts.append(part)
+
+ return ' '.join(parts)
+
+ def _format_text(self, text):
+ text_width = self._width - self._current_indent
+ indent = ' ' * self._current_indent
+ return self._fill_text(text, text_width, indent) + '\n\n'
+
+ def _format_action(self, action):
+ # determine the required width and the entry label
+ help_position = min(self._action_max_length + 2,
+ self._max_help_position)
+ help_width = self._width - help_position
+ action_width = help_position - self._current_indent - 2
+ action_header = self._format_action_invocation(action)
+
+ # ho nelp; start on same line and add a final newline
+ if not action.help:
+ tup = self._current_indent, '', action_header
+ action_header = '%*s%s\n' % tup
+
+ # short action name; start on the same line and pad two spaces
+ elif len(action_header) <= action_width:
+ tup = self._current_indent, '', action_width, action_header
+ action_header = '%*s%-*s ' % tup
+ indent_first = 0
+
+ # long action name; start on the next line
+ else:
+ tup = self._current_indent, '', action_header
+ action_header = '%*s%s\n' % tup
+ indent_first = help_position
+
+ # collect the pieces of the action help
+ parts = [action_header]
+
+ # if there was help for the action, add lines of help text
+ if action.help:
+ help_text = self._expand_help(action)
+ help_lines = self._split_lines(help_text, help_width)
+ parts.append('%*s%s\n' % (indent_first, '', help_lines[0]))
+ for line in help_lines[1:]:
+ parts.append('%*s%s\n' % (help_position, '', line))
+
+ # or add a newline if the description doesn't end with one
+ elif not action_header.endswith('\n'):
+ parts.append('\n')
+
+ # return a single string
+ return self._join_parts(parts)
+
+ def _format_action_invocation(self, action):
+ if not action.option_strings:
+ return self._format_metavar(action, action.dest)
+
+ else:
+ parts = []
+
+ # if the Optional doesn't take a value, format is:
+ # -s, --long
+ if action.nargs == 0:
+ parts.extend(action.option_strings)
+
+ # if the Optional takes a value, format is:
+ # -s ARGS, --long ARGS
+ else:
+ default = action.dest.upper()
+ args_string = self._format_args(action, default)
+ for option_string in action.option_strings:
+ parts.append('%s %s' % (option_string, args_string))
+
+ return ', '.join(parts)
+
+ def _format_metavar(self, action, default_metavar):
+ if action.metavar is not None:
+ name = action.metavar
+ elif action.choices is not None:
+ choice_strs = (str(choice) for choice in action.choices)
+ name = '{%s}' % ','.join(choice_strs)
+ else:
+ name = default_metavar
+ return name
+
+ def _format_args(self, action, default_metavar):
+ name = self._format_metavar(action, default_metavar)
+ if action.nargs is None:
+ result = name
+ elif action.nargs == OPTIONAL:
+ result = '[%s]' % name
+ elif action.nargs == ZERO_OR_MORE:
+ result = '[%s [%s ...]]' % (name, name)
+ elif action.nargs == ONE_OR_MORE:
+ result = '%s [%s ...]' % (name, name)
+ elif action.nargs is PARSER:
+ result = '%s ...' % name
+ else:
+ result = ' '.join([name] * action.nargs)
+ return result
+
+ def _expand_help(self, action):
+ params = dict(vars(action), prog=self._prog)
+ for name, value in params.items():
+ if value is SUPPRESS:
+ del params[name]
+ if params.get('choices') is not None:
+ choices_str = ', '.join(str(c) for c in params['choices'])
+ params['choices'] = choices_str
+ return action.help % params
+
+ def _split_lines(self, text, width):
+ text = self._whitespace_matcher.sub(' ', text).strip()
+ return _textwrap.wrap(text, width)
+
+ def _fill_text(self, text, width, indent):
+ text = self._whitespace_matcher.sub(' ', text).strip()
+ return _textwrap.fill(text, width, initial_indent=indent,
+ subsequent_indent=indent)
+
+class RawDescriptionHelpFormatter(HelpFormatter):
+
+ def _fill_text(self, text, width, indent):
+ return ''.join(indent + line for line in text.splitlines(True))
+
+class RawTextHelpFormatter(RawDescriptionHelpFormatter):
+
+ def _split_lines(self, text, width):
+ return text.splitlines()
+
+# =====================
+# Options and Arguments
+# =====================
+
+class ArgumentError(Exception):
+ """ArgumentError(message, argument)
+
+ Raised whenever there was an error creating or using an argument
+ (optional or positional).
+
+ The string value of this exception is the message, augmented with
+ information about the argument that caused it.
+ """
+
+ def __init__(self, argument, message):
+ if argument.option_strings:
+ self.argument_name = '/'.join(argument.option_strings)
+ elif argument.metavar not in (None, SUPPRESS):
+ self.argument_name = argument.metavar
+ elif argument.dest not in (None, SUPPRESS):
+ self.argument_name = argument.dest
+ else:
+ self.argument_name = None
+ self.message = message
+
+ def __str__(self):
+ if self.argument_name is None:
+ format = '%(message)s'
+ else:
+ format = 'argument %(argument_name)s: %(message)s'
+ return format % dict(message=self.message,
+ argument_name=self.argument_name)
+
+# ==============
+# Action classes
+# ==============
+
+class Action(_AttributeHolder):
+ """Action(*strings, **options)
+
+ Action objects hold the information necessary to convert a
+ set of command-line arguments (possibly including an initial option
+ string) into the desired Python object(s).
+
+ Keyword Arguments:
+
+ option_strings -- A list of command-line option strings which
+ should be associated with this action.
+
+ dest -- The name of the attribute to hold the created object(s)
+
+ nargs -- The number of command-line arguments that should be consumed.
+ By default, one argument will be consumed and a single value will
+ be produced. Other values include:
+ * N (an integer) consumes N arguments (and produces a list)
+ * '?' consumes zero or one arguments
+ * '*' consumes zero or more arguments (and produces a list)
+ * '+' consumes one or more arguments (and produces a list)
+ Note that the difference between the default and nargs=1 is that
+ with the default, a single value will be produced, while with
+ nargs=1, a list containing a single value will be produced.
+
+ const -- The value to be produced if the option is specified and the
+ option uses an action that takes no values.
+
+ default -- The value to be produced if the option is not specified.
+
+ type -- The type which the command-line arguments should be converted
+ to, should be one of 'string', 'int', 'float', 'complex' or a
+ callable object that accepts a single string argument. If None,
+ 'string' is assumed.
+
+ choices -- A container of values that should be allowed. If not None,
+ after a command-line argument has been converted to the appropriate
+ type, an exception will be raised if it is not a member of this
+ collection.
+
+ required -- True if the action must always be specified at the command
+ line. This is only meaningful for optional command-line arguments.
+
+ help -- The help string describing the argument.
+
+ metavar -- The name to be used for the option's argument with the help
+ string. If None, the 'dest' value will be used as the name.
+ """
+
+
+ def __init__(self,
+ option_strings,
+ dest,
+ nargs=None,
+ const=None,
+ default=None,
+ type=None,
+ choices=None,
+ required=False,
+ help=None,
+ metavar=None):
+ self.option_strings = option_strings
+ self.dest = dest
+ self.nargs = nargs
+ self.const = const
+ self.default = default
+ self.type = type
+ self.choices = choices
+ self.required = required
+ self.help = help
+ self.metavar = metavar
+
+ def _get_kwargs(self):
+ names = [
+ 'option_strings',
+ 'dest',
+ 'nargs',
+ 'const',
+ 'default',
+ 'type',
+ 'choices',
+ 'help',
+ 'metavar'
+ ]
+ return [(name, getattr(self, name)) for name in names]
+
+ def __call__(self, parser, namespace, values, option_string=None):
+ raise NotImplementedError(_('.__call__() not defined'))
+
+class _StoreAction(Action):
+ def __init__(self,
+ option_strings,
+ dest,
+ nargs=None,
+ const=None,
+ default=None,
+ type=None,
+ choices=None,
+ required=False,
+ help=None,
+ metavar=None):
+ if nargs == 0:
+ raise ValueError('nargs must be > 0')
+ if const is not None and nargs != OPTIONAL:
+ raise ValueError('nargs must be %r to supply const' % OPTIONAL)
+ super(_StoreAction, self).__init__(
+ option_strings=option_strings,
+ dest=dest,
+ nargs=nargs,
+ const=const,
+ default=default,
+ type=type,
+ choices=choices,
+ required=required,
+ help=help,
+ metavar=metavar)
+
+ def __call__(self, parser, namespace, values, option_string=None):
+ setattr(namespace, self.dest, values)
+
+class _StoreConstAction(Action):
+ def __init__(self,
+ option_strings,
+ dest,
+ const,
+ default=None,
+ required=False,
+ help=None,
+ metavar=None):
+ super(_StoreConstAction, self).__init__(
+ option_strings=option_strings,
+ dest=dest,
+ nargs=0,
+ const=const,
+ default=default,
+ required=required,
+ help=help)
+
+ def __call__(self, parser, namespace, values, option_string=None):
+ setattr(namespace, self.dest, self.const)
+
+class _StoreTrueAction(_StoreConstAction):
+ def __init__(self,
+ option_strings,
+ dest,
+ default=False,
+ required=False,
+ help=None):
+ super(_StoreTrueAction, self).__init__(
+ option_strings=option_strings,
+ dest=dest,
+ const=True,
+ default=default,
+ required=required,
+ help=help)
+
+class _StoreFalseAction(_StoreConstAction):
+ def __init__(self,
+ option_strings,
+ dest,
+ default=True,
+ required=False,
+ help=None):
+ super(_StoreFalseAction, self).__init__(
+ option_strings=option_strings,
+ dest=dest,
+ const=False,
+ default=default,
+ required=required,
+ help=help)
+
+class _AppendAction(Action):
+ def __init__(self,
+ option_strings,
+ dest,
+ nargs=None,
+ const=None,
+ default=None,
+ type=None,
+ choices=None,
+ required=False,
+ help=None,
+ metavar=None):
+ if nargs == 0:
+ raise ValueError('nargs must be > 0')
+ if const is not None and nargs != OPTIONAL:
+ raise ValueError('nargs must be %r to supply const' % OPTIONAL)
+ super(_AppendAction, self).__init__(
+ option_strings=option_strings,
+ dest=dest,
+ nargs=nargs,
+ const=const,
+ default=default,
+ type=type,
+ choices=choices,
+ required=required,
+ help=help,
+ metavar=metavar)
+
+ def __call__(self, parser, namespace, values, option_string=None):
+ _ensure_value(namespace, self.dest, []).append(values)
+
+class _AppendConstAction(Action):
+ def __init__(self,
+ option_strings,
+ dest,
+ const,
+ default=None,
+ required=False,
+ help=None,
+ metavar=None):
+ super(_AppendConstAction, self).__init__(
+ option_strings=option_strings,
+ dest=dest,
+ nargs=0,
+ const=const,
+ default=default,
+ required=required,
+ help=help,
+ metavar=metavar)
+
+ def __call__(self, parser, namespace, values, option_string=None):
+ _ensure_value(namespace, self.dest, []).append(self.const)
+
+class _CountAction(Action):
+ def __init__(self,
+ option_strings,
+ dest,
+ default=None,
+ required=False,
+ help=None):
+ super(_CountAction, self).__init__(
+ option_strings=option_strings,
+ dest=dest,
+ nargs=0,
+ default=default,
+ required=required,
+ help=help)
+
+ def __call__(self, parser, namespace, values, option_string=None):
+ new_count = _ensure_value(namespace, self.dest, 0) + 1
+ setattr(namespace, self.dest, new_count)
+
+class _HelpAction(Action):
+ def __init__(self,
+ option_strings,
+ dest,
+ help=None):
+ super(_HelpAction, self).__init__(
+ option_strings=option_strings,
+ dest=SUPPRESS,
+ nargs=0,
+ help=help)
+
+ def __call__(self, parser, namespace, values, option_string=None):
+ parser.print_help()
+ parser.exit()
+
+class _VersionAction(Action):
+ def __init__(self,
+ option_strings,
+ dest,
+ help=None):
+ super(_VersionAction, self).__init__(
+ option_strings=option_strings,
+ dest=SUPPRESS,
+ nargs=0,
+ help=help)
+
+ def __call__(self, parser, namespace, values, option_string=None):
+ parser.print_version()
+ parser.exit()
+
+class _SubParsersAction(Action):
+
+ def __init__(self,
+ option_strings,
+ prog,
+ parser_class,
+ dest=SUPPRESS,
+ help=None,
+ metavar=None):
+
+ self._prog_prefix = prog
+ self._parser_class = parser_class
+ self._name_parser_map = {}
+
+ super(_SubParsersAction, self).__init__(
+ option_strings=option_strings,
+ dest=dest,
+ nargs=PARSER,
+ choices=self._name_parser_map,
+ help=help,
+ metavar=metavar)
+
+ def add_parser(self, name, **kwargs):
+ if kwargs.get('prog') is None:
+ kwargs['prog'] = '%s %s' % (self._prog_prefix, name)
+
+ parser = self._parser_class(**kwargs)
+ self._name_parser_map[name] = parser
+ return parser
+
+ def __call__(self, parser, namespace, values, option_string=None):
+ parser_name = values[0]
+ arg_strings = values[1:]
+
+ # set the parser name if requested
+ if self.dest is not SUPPRESS:
+ setattr(namespace, self.dest, parser_name)
+
+ # select the parser
+ try:
+ parser = self._name_parser_map[parser_name]
+ except KeyError:
+ tup = parser_name, ', '.join(self._name_parser_map)
+ msg = _('unknown parser %r (choices: %s)' % tup)
+ raise ArgumentError(self, msg)
+
+ # parse all the remaining options into the namespace
+ parser.parse_args(arg_strings, namespace)
+
+
+# ==============
+# Type classes
+# ==============
+
+class FileType(object):
+ """Factory for creating file object types
+
+ Instances of FileType are typically passed as type= arguments to the
+ ArgumentParser add_argument() method.
+
+ Keyword Arguments:
+ mode -- A string indicating how the file is to be opened. Accepts the
+ same values as the builtin open() function.
+ bufsize -- The file's desired buffer size. Accepts the same values as
+ the builtin open() function.
+ """
+ def __init__(self, mode='r', bufsize=None):
+ self._mode = mode
+ self._bufsize = bufsize
+
+ def __call__(self, string):
+ # the special argument "-" means sys.std{in,out}
+ if string == '-':
+ if self._mode == 'r':
+ return _sys.stdin
+ elif self._mode == 'w':
+ return _sys.stdout
+ else:
+ msg = _('argument "-" with mode %r' % self._mode)
+ raise ValueError(msg)
+
+ # all other arguments are used as file names
+ if self._bufsize:
+ return open(string, self._mode, self._bufsize)
+ else:
+ return open(string, self._mode)
+
+
+# ===========================
+# Optional and Positional Parsing
+# ===========================
+
+class Namespace(_AttributeHolder):
+
+ def __init__(self, **kwargs):
+ for name, value in kwargs.iteritems():
+ setattr(self, name, value)
+
+ def __eq__(self, other):
+ return vars(self) == vars(other)
+
+ def __ne__(self, other):
+ return not (self == other)
+
+
+class _ActionsContainer(object):
+ def __init__(self,
+ description,
+ conflict_handler):
+ superinit = super(_ActionsContainer, self).__init__
+ superinit(description=description)
+
+ self.description = description
+ self.conflict_handler = conflict_handler
+
+ # set up registries
+ self._registries = {}
+
+ # register actions
+ self.register('action', None, _StoreAction)
+ self.register('action', 'store', _StoreAction)
+ self.register('action', 'store_const', _StoreConstAction)
+ self.register('action', 'store_true', _StoreTrueAction)
+ self.register('action', 'store_false', _StoreFalseAction)
+ self.register('action', 'append', _AppendAction)
+ self.register('action', 'append_const', _AppendConstAction)
+ self.register('action', 'count', _CountAction)
+ self.register('action', 'help', _HelpAction)
+ self.register('action', 'version', _VersionAction)
+ self.register('action', 'parsers', _SubParsersAction)
+
+ # raise an exception if the conflict handler is invalid
+ self._get_handler()
+
+ # action storage
+ self._optional_actions_list = []
+ self._positional_actions_list = []
+ self._positional_actions_full_list = []
+ self._option_strings = {}
+
+ # ====================
+ # Registration methods
+ # ====================
+
+ def register(self, registry_name, value, object):
+ registry = self._registries.setdefault(registry_name, {})
+ registry[value] = object
+
+ def _registry_get(self, registry_name, value, default=None):
+ return self._registries[registry_name].get(value, default)
+
+ # =======================
+ # Adding argument actions
+ # =======================
+
+ def add_argument(self, *args, **kwargs):
+ """
+ add_argument(dest, ..., name=value, ...)
+ add_argument(option_string, option_string, ..., name=value, ...)
+ """
+
+ # type='outfile' is deprecated
+ if kwargs.get('type') == 'outfile':
+ import warnings
+ msg = _("use type=FileType('w') instead of type='outfile'")
+ warnings.warn(msg, DeprecationWarning)
+
+ # if no positional args are supplied or only one is supplied and
+ # it doesn't look like an option string, parse a positional
+ # argument
+ if not args or len(args) == 1 and args[0][0] != '-':
+ kwargs = self._get_positional_kwargs(*args, **kwargs)
+
+ # otherwise, we're adding an optional argument
+ else:
+ kwargs = self._get_optional_kwargs(*args, **kwargs)
+
+ # create the action object, and add it to the parser
+ action_class = self._pop_action_class(kwargs)
+ action = action_class(**kwargs)
+ return self._add_action(action)
+
+ def _add_action(self, action):
+ # resolve any conflicts
+ self._check_conflict(action)
+
+ # add to optional or positional list
+ if action.option_strings:
+ self._optional_actions_list.append(action)
+ else:
+ self._positional_actions_list.append(action)
+ self._positional_actions_full_list.append(action)
+ action.container = self
+
+ # index the action by any option strings it has
+ for option_string in action.option_strings:
+ self._option_strings[option_string] = action
+
+ # return the created action
+ return action
+
+ def _add_container_actions(self, container):
+ for action in container._optional_actions_list:
+ self._add_action(action)
+ for action in container._positional_actions_list:
+ self._add_action(action)
+
+ def _get_positional_kwargs(self, dest, **kwargs):
+ # make sure required is not specified
+ if 'required' in kwargs:
+ msg = _("'required' is an invalid argument for positionals")
+ raise TypeError(msg)
+
+ # return the keyword arguments with no option strings
+ return dict(kwargs, dest=dest, option_strings=[])
+
+ def _get_optional_kwargs(self, *args, **kwargs):
+ # determine short and long option strings
+ option_strings = []
+ long_option_strings = []
+ for option_string in args:
+ # error on one-or-fewer-character option strings
+ if len(option_string) < 2:
+ msg = _('invalid option string %r: '
+ 'must be at least two characters long')
+ raise ValueError(msg % option_string)
+
+ # error on strings that don't start with '-'
+ if not option_string.startswith('-'):
+ msg = _('invalid option string %r: '
+ 'does not start with "-"')
+ raise ValueError(msg % option_string)
+
+ # error on strings that are all '-'s
+ if not option_string.replace('-', ''):
+ msg = _('invalid option string %r: '
+ 'must contain characters other than "-"')
+ raise ValueError(msg % option_string)
+
+ # strings starting with '--' are long options
+ option_strings.append(option_string)
+ if option_string.startswith('--'):
+ long_option_strings.append(option_string)
+
+ # infer destination, '--foo-bar' -> 'foo_bar' and '-x' -> 'x'
+ dest = kwargs.pop('dest', None)
+ if dest is None:
+ if long_option_strings:
+ dest_option_string = long_option_strings[0]
+ else:
+ dest_option_string = option_strings[0]
+ dest = dest_option_string.lstrip('-').replace('-', '_')
+
+ # return the updated keyword arguments
+ return dict(kwargs, dest=dest, option_strings=option_strings)
+
+ def _pop_action_class(self, kwargs, default=None):
+ action = kwargs.pop('action', default)
+ return self._registry_get('action', action, action)
+
+ def _get_handler(self):
+ # determine function from conflict handler string
+ handler_func_name = '_handle_conflict_%s' % self.conflict_handler
+ try:
+ return getattr(self, handler_func_name)
+ except AttributeError:
+ msg = _('invalid conflict_resolution value: %r')
+ raise ValueError(msg % self.conflict_handler)
+
+ def _check_conflict(self, action):
+
+ # find all options that conflict with this option
+ confl_optionals = []
+ for option_string in action.option_strings:
+ if option_string in self._option_strings:
+ confl_optional = self._option_strings[option_string]
+ confl_optionals.append((option_string, confl_optional))
+
+ # resolve any conflicts
+ if confl_optionals:
+ conflict_handler = self._get_handler()
+ conflict_handler(action, confl_optionals)
+
+ def _handle_conflict_error(self, action, conflicting_actions):
+ message = _('conflicting option string(s): %s')
+ conflict_string = ', '.join(option_string
+ for option_string, action
+ in conflicting_actions)
+ raise ArgumentError(action, message % conflict_string)
+
+ def _handle_conflict_resolve(self, action, conflicting_actions):
+
+ # remove all conflicting options
+ for option_string, action in conflicting_actions:
+
+ # remove the conflicting option
+ action.option_strings.remove(option_string)
+ self._option_strings.pop(option_string, None)
+
+ # if the option now has no option string, remove it from the
+ # container holding it
+ if not action.option_strings:
+ action.container._optional_actions_list.remove(action)
+
+
+class _ArgumentGroup(_ActionsContainer):
+
+ def __init__(self, container, title=None, description=None, **kwargs):
+ # add any missing keyword arguments by checking the container
+ update = kwargs.setdefault
+ update('conflict_handler', container.conflict_handler)
+ superinit = super(_ArgumentGroup, self).__init__
+ superinit(description=description, **kwargs)
+
+ self.title = title
+ self._registries = container._registries
+ self._positional_actions_full_list = container._positional_actions_full_list
+ self._option_strings = container._option_strings
+
+
+class ArgumentParser(_AttributeHolder, _ActionsContainer):
+
+ def __init__(self,
+ prog=None,
+ usage=None,
+ description=None,
+ epilog=None,
+ version=None,
+ parents=[],
+ formatter_class=HelpFormatter,
+ conflict_handler='error',
+ add_help=True):
+
+ superinit = super(ArgumentParser, self).__init__
+ superinit(description=description,
+ conflict_handler=conflict_handler)
+
+ # default setting for prog
+ if prog is None:
+ prog = _os.path.basename(_sys.argv[0])
+
+ self.prog = prog
+ self.usage = usage
+ self.epilog = epilog
+ self.version = version
+ self.formatter_class = formatter_class
+ self.add_help = add_help
+
+ self._argument_group_class = _ArgumentGroup
+ self._has_subparsers = False
+ self._argument_groups = []
+ self._defaults = {}
+
+ # register types
+ def identity(string):
+ return string
+ def outfile(string):
+ if string == '-':
+ return _sys.stdout
+ else:
+ return open(string, 'w')
+ self.register('type', None, identity)
+ self.register('type', 'outfile', outfile)
+
+ # add help and version arguments if necessary
+ if self.add_help:
+ self._add_help_argument()
+ if self.version:
+ self._add_version_argument()
+
+ # add parent arguments and defaults
+ for parent in parents:
+ self._add_container_actions(parent)
+ try:
+ defaults = parent._defaults
+ except AttributeError:
+ pass
+ else:
+ self._defaults.update(defaults)
+
+ # determines whether an "option" looks like a negative number
+ self._negative_number_matcher = _re.compile(r'^-\d+|-\d*.\d+$')
+
+
+ # =======================
+ # Pretty __repr__ methods
+ # =======================
+
+ def _get_kwargs(self):
+ names = [
+ 'prog',
+ 'usage',
+ 'description',
+ 'version',
+ 'formatter_class',
+ 'conflict_handler',
+ 'add_help',
+ ]
+ return [(name, getattr(self, name)) for name in names]
+
+ # ==================================
+ # Namespace default settings methods
+ # ==================================
+
+ def set_defaults(self, **kwargs):
+ self._defaults.update(kwargs)
+
+ # ==================================
+ # Optional/Positional adding methods
+ # ==================================
+
+ def add_argument_group(self, *args, **kwargs):
+ group = self._argument_group_class(self, *args, **kwargs)
+ self._argument_groups.append(group)
+ return group
+
+ def add_subparsers(self, **kwargs):
+ if self._has_subparsers:
+ self.error(_('cannot have multiple subparser arguments'))
+
+ # add the parser class to the arguments if it's not present
+ kwargs.setdefault('parser_class', type(self))
+
+ # prog defaults to the usage message of this parser, skipping
+ # optional arguments and with no "usage:" prefix
+ if kwargs.get('prog') is None:
+ formatter = self._get_formatter()
+ formatter.add_usage(self.usage, [],
+ self._get_positional_actions(), '')
+ kwargs['prog'] = formatter.format_help().strip()
+
+ # create the parsers action and add it to the positionals list
+ parsers_class = self._pop_action_class(kwargs, 'parsers')
+ action = parsers_class(option_strings=[], **kwargs)
+ self._positional_actions_list.append(action)
+ self._positional_actions_full_list.append(action)
+ self._has_subparsers = True
+
+ # return the created parsers action
+ return action
+
+ def _add_container_actions(self, container):
+ super(ArgumentParser, self)._add_container_actions(container)
+ try:
+ groups = container._argument_groups
+ except AttributeError:
+ pass
+ else:
+ for group in groups:
+ new_group = self.add_argument_group(
+ title=group.title,
+ description=group.description,
+ conflict_handler=group.conflict_handler)
+ new_group._add_container_actions(group)
+
+ def _get_optional_actions(self):
+ actions = []
+ actions.extend(self._optional_actions_list)
+ for argument_group in self._argument_groups:
+ actions.extend(argument_group._optional_actions_list)
+ return actions
+
+ def _get_positional_actions(self):
+ return list(self._positional_actions_full_list)
+
+ def _add_help_argument(self):
+ self.add_argument('-h', '--help', action='help',
+ help=_('show this help message and exit'))
+
+ def _add_version_argument(self):
+ self.add_argument('-v', '--version', action='version',
+ help=_("show program's version number and exit"))
+
+
+ # =====================================
+ # Command line argument parsing methods
+ # =====================================
+
+ def parse_args(self, args=None, namespace=None):
+ # args default to the system args
+ if args is None:
+ args = _sys.argv[1:]
+
+ # default Namespace built from parser defaults
+ if namespace is None:
+ namespace = Namespace()
+
+ # add any action defaults that aren't present
+ optional_actions = self._get_optional_actions()
+ positional_actions = self._get_positional_actions()
+ for action in optional_actions + positional_actions:
+ if action.dest is not SUPPRESS:
+ if not hasattr(namespace, action.dest):
+ if action.default is not SUPPRESS:
+ default = action.default
+ if isinstance(action.default, basestring):
+ default = self._get_value(action, default)
+ setattr(namespace, action.dest, default)
+
+ # add any parser defaults that aren't present
+ for dest, value in self._defaults.iteritems():
+ if not hasattr(namespace, dest):
+ setattr(namespace, dest, value)
+
+ # parse the arguments and exit if there are any errors
+ try:
+ result = self._parse_args(args, namespace)
+ except ArgumentError, err:
+ self.error(str(err))
+
+ # make sure all required optionals are present
+ for action in self._get_optional_actions():
+ if action.required:
+ if getattr(result, action.dest, None) is None:
+ opt_strs = '/'.join(action.option_strings)
+ msg = _('option %s is required' % opt_strs)
+ self.error(msg)
+
+ # return the parsed arguments
+ return result
+
+ def _parse_args(self, arg_strings, namespace):
+
+ # find all option indices, and determine the arg_string_pattern
+ # which has an 'O' if there is an option at an index,
+ # an 'A' if there is an argument, or a '-' if there is a '--'
+ option_string_indices = {}
+ arg_string_pattern_parts = []
+ arg_strings_iter = iter(arg_strings)
+ for i, arg_string in enumerate(arg_strings_iter):
+
+ # all args after -- are non-options
+ if arg_string == '--':
+ arg_string_pattern_parts.append('-')
+ for arg_string in arg_strings_iter:
+ arg_string_pattern_parts.append('A')
+
+ # otherwise, add the arg to the arg strings
+ # and note the index if it was an option
+ else:
+ option_tuple = self._parse_optional(arg_string)
+ if option_tuple is None:
+ pattern = 'A'
+ else:
+ option_string_indices[i] = option_tuple
+ pattern = 'O'
+ arg_string_pattern_parts.append(pattern)
+
+ # join the pieces together to form the pattern
+ arg_strings_pattern = ''.join(arg_string_pattern_parts)
+
+ # converts arg strings to the appropriate and then takes the action
+ def take_action(action, argument_strings, option_string=None):
+ argument_values = self._get_values(action, argument_strings)
+ action(self, namespace, argument_values, option_string)
+
+ # function to convert arg_strings into an optional action
+ def consume_optional(start_index):
+
+ # determine the optional action and parse any explicit
+ # argument out of the option string
+ option_tuple = option_string_indices[start_index]
+ action, option_string, explicit_arg = option_tuple
+
+ # loop because single-dash options can be chained
+ # (e.g. -xyz is the same as -x -y -z if no args are required)
+ match_argument = self._match_argument
+ action_tuples = []
+ while True:
+
+ # if we found no optional action, raise an error
+ if action is None:
+ self.error(_('no such option: %s') % option_string)
+
+ # if there is an explicit argument, try to match the
+ # optional's string arguments to only this
+ if explicit_arg is not None:
+ arg_count = match_argument(action, 'A')
+
+ # if the action is a single-dash option and takes no
+ # arguments, try to parse more single-dash options out
+ # of the tail of the option string
+ if arg_count == 0 and option_string[1] != '-':
+ action_tuples.append((action, [], option_string))
+ option_string = '-' + explicit_arg
+ option_tuple = self._parse_optional(option_string)
+ if option_tuple[0] is None:
+ msg = _('ignored explicit argument %r')
+ raise ArgumentError(action, msg % explicit_arg)
+
+ # set the action, etc. for the next loop iteration
+ action, option_string, explicit_arg = option_tuple
+
+ # if the action expect exactly one argument, we've
+ # successfully matched the option; exit the loop
+ elif arg_count == 1:
+ stop = start_index + 1
+ args = [explicit_arg]
+ action_tuples.append((action, args, option_string))
+ break
+
+ # error if a double-dash option did not use the
+ # explicit argument
+ else:
+ msg = _('ignored explicit argument %r')
+ raise ArgumentError(action, msg % explicit_arg)
+
+ # if there is no explicit argument, try to match the
+ # optional's string arguments with the following strings
+ # if successful, exit the loop
+ else:
+ start = start_index + 1
+ selected_patterns = arg_strings_pattern[start:]
+ arg_count = match_argument(action, selected_patterns)
+ stop = start + arg_count
+ args = arg_strings[start:stop]
+ action_tuples.append((action, args, option_string))
+ break
+
+ # add the Optional to the list and return the index at which
+ # the Optional's string args stopped
+ assert action_tuples
+ for action, args, option_string in action_tuples:
+ take_action(action, args, option_string)
+ return stop
+
+ # the list of Positionals left to be parsed; this is modified
+ # by consume_positionals()
+ positionals = self._get_positional_actions()
+
+ # function to convert arg_strings into positional actions
+ def consume_positionals(start_index):
+ # match as many Positionals as possible
+ match_partial = self._match_arguments_partial
+ selected_pattern = arg_strings_pattern[start_index:]
+ arg_counts = match_partial(positionals, selected_pattern)
+
+ # slice off the appropriate arg strings for each Positional
+ # and add the Positional and its args to the list
+ for action, arg_count in zip(positionals, arg_counts):
+ args = arg_strings[start_index: start_index + arg_count]
+ start_index += arg_count
+ take_action(action, args)
+
+ # slice off the Positionals that we just parsed and return the
+ # index at which the Positionals' string args stopped
+ positionals[:] = positionals[len(arg_counts):]
+ return start_index
+
+ # consume Positionals and Optionals alternately, until we have
+ # passed the last option string
+ start_index = 0
+ if option_string_indices:
+ max_option_string_index = max(option_string_indices)
+ else:
+ max_option_string_index = -1
+ while start_index <= max_option_string_index:
+
+ # consume any Positionals preceding the next option
+ next_option_string_index = min(
+ index
+ for index in option_string_indices
+ if index >= start_index)
+ if start_index != next_option_string_index:
+ positionals_end_index = consume_positionals(start_index)
+
+ # only try to parse the next optional if we didn't consume
+ # the option string during the positionals parsing
+ if positionals_end_index > start_index:
+ start_index = positionals_end_index
+ continue
+ else:
+ start_index = positionals_end_index
+
+ # if we consumed all the positionals we could and we're not
+ # at the index of an option string, there were unparseable
+ # arguments
+ if start_index not in option_string_indices:
+ msg = _('extra arguments found: %s')
+ extras = arg_strings[start_index:next_option_string_index]
+ self.error(msg % ' '.join(extras))
+
+ # consume the next optional and any arguments for it
+ start_index = consume_optional(start_index)
+
+ # consume any positionals following the last Optional
+ stop_index = consume_positionals(start_index)
+
+ # if we didn't consume all the argument strings, there were too
+ # many supplied
+ if stop_index != len(arg_strings):
+ extras = arg_strings[stop_index:]
+ self.error(_('extra arguments found: %s') % ' '.join(extras))
+
+ # if we didn't use all the Positional objects, there were too few
+ # arg strings supplied.
+ if positionals:
+ self.error(_('too few arguments'))
+
+ # return the updated namespace
+ return namespace
+
+ def _match_argument(self, action, arg_strings_pattern):
+ # match the pattern for this action to the arg strings
+ nargs_pattern = self._get_nargs_pattern(action)
+ match = _re.match(nargs_pattern, arg_strings_pattern)
+
+ # raise an exception if we weren't able to find a match
+ if match is None:
+ nargs_errors = {
+ None:_('expected one argument'),
+ OPTIONAL:_('expected at most one argument'),
+ ONE_OR_MORE:_('expected at least one argument')
+ }
+ default = _('expected %s argument(s)') % action.nargs
+ msg = nargs_errors.get(action.nargs, default)
+ raise ArgumentError(action, msg)
+
+ # return the number of arguments matched
+ return len(match.group(1))
+
+ def _match_arguments_partial(self, actions, arg_strings_pattern):
+ # progressively shorten the actions list by slicing off the
+ # final actions until we find a match
+ result = []
+ for i in xrange(len(actions), 0, -1):
+ actions_slice = actions[:i]
+ pattern = ''.join(self._get_nargs_pattern(action)
+ for action in actions_slice)
+ match = _re.match(pattern, arg_strings_pattern)
+ if match is not None:
+ result.extend(len(string) for string in match.groups())
+ break
+
+ # return the list of arg string counts
+ return result
+
+ def _parse_optional(self, arg_string):
+ # if it doesn't start with a '-', it was meant to be positional
+ if not arg_string.startswith('-'):
+ return None
+
+ # if it's just dashes, it was meant to be positional
+ if not arg_string.strip('-'):
+ return None
+
+ # if the option string is present in the parser, return the action
+ if arg_string in self._option_strings:
+ action = self._option_strings[arg_string]
+ return action, arg_string, None
+
+ # search through all possible prefixes of the option string
+ # and all actions in the parser for possible interpretations
+ option_tuples = []
+ prefix_tuples = self._get_option_prefix_tuples(arg_string)
+ for option_string in self._option_strings:
+ for option_prefix, explicit_arg in prefix_tuples:
+ if option_string.startswith(option_prefix):
+ action = self._option_strings[option_string]
+ tup = action, option_string, explicit_arg
+ option_tuples.append(tup)
+ break
+
+ # if multiple actions match, the option string was ambiguous
+ if len(option_tuples) > 1:
+ options = ', '.join(opt_str for _, opt_str, _ in option_tuples)
+ tup = arg_string, options
+ self.error(_('ambiguous option: %s could match %s') % tup)
+
+ # if exactly one action matched, this segmentation is good,
+ # so return the parsed action
+ elif len(option_tuples) == 1:
+ option_tuple, = option_tuples
+ return option_tuple
+
+ # if it was not found as an option, but it looks like a negative
+ # number, it was meant to be positional
+ if self._negative_number_matcher.match(arg_string):
+ return None
+
+ # it was meant to be an optional but there is no such option
+ # in this parser (though it might be a valid option in a subparser)
+ return None, arg_string, None
+
+ def _get_option_prefix_tuples(self, option_string):
+ result = []
+
+ # option strings starting with '--' are only split at the '='
+ if option_string.startswith('--'):
+ if '=' in option_string:
+ option_prefix, explicit_arg = option_string.split('=', 1)
+ else:
+ option_prefix = option_string
+ explicit_arg = None
+ tup = option_prefix, explicit_arg
+ result.append(tup)
+
+ # option strings starting with '-' are split at all indices
+ else:
+ for first_index, char in enumerate(option_string):
+ if char != '-':
+ break
+ for i in xrange(len(option_string), first_index, -1):
+ tup = option_string[:i], option_string[i:] or None
+ result.append(tup)
+
+ # return the collected prefix tuples
+ return result
+
+ def _get_nargs_pattern(self, action):
+ # in all examples below, we have to allow for '--' args
+ # which are represented as '-' in the pattern
+ nargs = action.nargs
+
+ # the default (None) is assumed to be a single argument
+ if nargs is None:
+ nargs_pattern = '(-*A-*)'
+
+ # allow zero or one arguments
+ elif nargs == OPTIONAL:
+ nargs_pattern = '(-*A?-*)'
+
+ # allow zero or more arguments
+ elif nargs == ZERO_OR_MORE:
+ nargs_pattern = '(-*[A-]*)'
+
+ # allow one or more arguments
+ elif nargs == ONE_OR_MORE:
+ nargs_pattern = '(-*A[A-]*)'
+
+ # allow one argument followed by any number of options or arguments
+ elif nargs is PARSER:
+ nargs_pattern = '(-*A[-AO]*)'
+
+ # all others should be integers
+ else:
+ nargs_pattern = '(-*%s-*)' % '-*'.join('A' * nargs)
+
+ # if this is an optional action, -- is not allowed
+ if action.option_strings:
+ nargs_pattern = nargs_pattern.replace('-*', '')
+ nargs_pattern = nargs_pattern.replace('-', '')
+
+ # return the pattern
+ return nargs_pattern
+
+ # ========================
+ # Value conversion methods
+ # ========================
+
+ def _get_values(self, action, arg_strings):
+ # for everything but PARSER args, strip out '--'
+ if action.nargs is not PARSER:
+ arg_strings = [s for s in arg_strings if s != '--']
+
+ # optional argument produces a default when not present
+ if not arg_strings and action.nargs == OPTIONAL:
+ if action.option_strings:
+ value = action.const
+ else:
+ value = action.default
+ if isinstance(value, basestring):
+ value = self._get_value(action, value)
+ self._check_value(action, value)
+
+ # when nargs='*' on a positional, if there were no command-line
+ # args, use the default if it is anything other than None
+ elif (not arg_strings and action.nargs == ZERO_OR_MORE and
+ not action.option_strings):
+ if action.default is not None:
+ value = action.default
+ else:
+ value = arg_strings
+ self._check_value(action, value)
+
+ # single argument or optional argument produces a single value
+ elif len(arg_strings) == 1 and action.nargs in [None, OPTIONAL]:
+ arg_string, = arg_strings
+ value = self._get_value(action, arg_string)
+ self._check_value(action, value)
+
+ # PARSER arguments convert all values, but check only the first
+ elif action.nargs is PARSER:
+ value = list(self._get_value(action, v) for v in arg_strings)
+ self._check_value(action, value[0])
+
+ # all other types of nargs produce a list
+ else:
+ value = list(self._get_value(action, v) for v in arg_strings)
+ for v in value:
+ self._check_value(action, v)
+
+ # return the converted value
+ return value
+
+ def _get_value(self, action, arg_string):
+ type_func = self._registry_get('type', action.type, action.type)
+ if not callable(type_func):
+ msg = _('%r is not callable')
+ raise ArgumentError(action, msg % type_func)
+
+ # convert the value to the appropriate type
+ try:
+ result = type_func(arg_string)
+
+ # TypeErrors or ValueErrors indicate errors
+ except (TypeError, ValueError):
+ name = getattr(action.type, '__name__', repr(action.type))
+ msg = _('invalid %s value: %r')
+ raise ArgumentError(action, msg % (name, arg_string))
+
+ # return the converted value
+ return result
+
+ def _check_value(self, action, value):
+ # converted value must be one of the choices (if specified)
+ if action.choices is not None and value not in action.choices:
+ tup = value, ', '.join(map(repr, action.choices))
+ msg = _('invalid choice: %r (choose from %s)') % tup
+ raise ArgumentError(action, msg)
+
+
+
+ # =======================
+ # Help-formatting methods
+ # =======================
+
+ def format_usage(self):
+ formatter = self._get_formatter()
+ formatter.add_usage(self.usage,
+ self._get_optional_actions(),
+ self._get_positional_actions())
+ return formatter.format_help()
+
+ def format_help(self):
+ formatter = self._get_formatter()
+
+ # usage
+ formatter.add_usage(self.usage,
+ self._get_optional_actions(),
+ self._get_positional_actions())
+
+ # description
+ formatter.add_text(self.description)
+
+ # positionals
+ formatter.start_section(_('positional arguments'))
+ formatter.add_arguments(self._positional_actions_list)
+ formatter.end_section()
+
+ # optionals
+ formatter.start_section(_('optional arguments'))
+ formatter.add_arguments(self._optional_actions_list)
+ formatter.end_section()
+
+ # user-defined groups
+ for argument_group in self._argument_groups:
+ formatter.start_section(argument_group.title)
+ formatter.add_text(argument_group.description)
+ formatter.add_arguments(argument_group._positional_actions_list)
+ formatter.add_arguments(argument_group._optional_actions_list)
+ formatter.end_section()
+
+ # epilog
+ formatter.add_text(self.epilog)
+
+ # determine help from format above
+ return formatter.format_help()
+
+ def format_version(self):
+ formatter = self._get_formatter()
+ formatter.add_text(self.version)
+ return formatter.format_help()
+
+ def _get_formatter(self):
+ return self.formatter_class(prog=self.prog)
+
+ # =====================
+ # Help-printing methods
+ # =====================
+
+ def print_usage(self, file=None):
+ self._print_message(self.format_usage(), file)
+
+ def print_help(self, file=None):
+ self._print_message(self.format_help(), file)
+
+ def print_version(self, file=None):
+ self._print_message(self.format_version(), file)
+
+ def _print_message(self, message, file=None):
+ if message:
+ if file is None:
+ file = _sys.stderr
+ file.write(message)
+
+
+ # ===============
+ # Exiting methods
+ # ===============
+
+ def exit(self, status=0, message=None):
+ if message:
+ _sys.stderr.write(message)
+ _sys.exit(status)
+
+ def 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.
+ """
+ self.print_usage(_sys.stderr)
+ self.exit(2, _('%s: error: %s\n') % (self.prog, message))
projects / tahoe-lafs / zfec.git / commitdiff