From: Zooko O'Whielacronx zooko@zooko.com Date: Sat, 14 Apr 2007 18:05:54 +0000 (+0530) Subject: pyfec: import a copy of the argparse module X-Git-Url: https://git.rkrishnan.org/%5B/%5D%20/uri/flags/readonly?a=commitdiff_plain;h=da42f94b4c7ded59aea5da428696ae867daa9a11;p=tahoe-lafs%2Fzfec.git pyfec: import a copy of the argparse module darcs-hash:778998cca426513dc19c55aa98f68f4f7fadca72 --- diff --git a/pyfec/fec/util/argparse.py b/pyfec/fec/util/argparse.py new file mode 100644 index 0000000..e615910 --- /dev/null +++ b/pyfec/fec/util/argparse.py @@ -0,0 +1,1793 @@ +# -*- coding: utf-8 -*- + +# Copyright © 2006 Steven J. Bethard . +# +# 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))