| # Author: Steven J. Bethard <steven.bethard@gmail.com>. |
| |
| """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, RawTextHelpFormatter, |
| ArgumentDefaultsHelpFormatter -- Formatter classes which |
| may be passed as the formatter_class= argument to the |
| ArgumentParser constructor. HelpFormatter is the default, |
| RawDescriptionHelpFormatter and RawTextHelpFormatter tell the parser |
| not to change the formatting for help text, and |
| ArgumentDefaultsHelpFormatter adds information about argument defaults |
| to the help. |
| |
| 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.) |
| """ |
| |
| __version__ = '1.1' |
| __all__ = [ |
| 'ArgumentParser', |
| 'ArgumentError', |
| 'ArgumentTypeError', |
| 'FileType', |
| 'HelpFormatter', |
| 'ArgumentDefaultsHelpFormatter', |
| 'RawDescriptionHelpFormatter', |
| 'RawTextHelpFormatter', |
| 'MetavarTypeHelpFormatter', |
| 'Namespace', |
| 'Action', |
| 'ONE_OR_MORE', |
| 'OPTIONAL', |
| 'PARSER', |
| 'REMAINDER', |
| 'SUPPRESS', |
| 'ZERO_OR_MORE', |
| ] |
| |
| |
| import collections as _collections |
| import copy as _copy |
| import os as _os |
| import re as _re |
| import sys as _sys |
| import textwrap as _textwrap |
| |
| from gettext import gettext as _, ngettext |
| |
| |
| SUPPRESS = '==SUPPRESS==' |
| |
| OPTIONAL = '?' |
| ZERO_OR_MORE = '*' |
| ONE_OR_MORE = '+' |
| PARSER = 'A...' |
| REMAINDER = '...' |
| _UNRECOGNIZED_ARGS_ATTR = '_unrecognized_args' |
| |
| # ============================= |
| # 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): |
| """Formatter for generating usage messages and argument help strings. |
| |
| Only the name of this class is considered a public API. All the methods |
| provided by the class are considered an implementation detail. |
| """ |
| |
| 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._max_help_position = min(max_help_position, |
| max(width - 20, indent_increment * 2)) |
| 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, actions, groups, prefix=None): |
| if usage is not SUPPRESS: |
| args = usage, actions, groups, prefix |
| self._add_item(self._format_usage, args) |
| |
| def add_argument(self, action): |
| if action.help is not SUPPRESS: |
| |
| # find all invocations |
| get_invocation = self._format_action_invocation |
| invocations = [get_invocation(action)] |
| for subaction in self._iter_indented_subactions(action): |
| invocations.append(get_invocation(subaction)) |
| |
| # update the maximum item length |
| invocation_length = max([len(s) for s in invocations]) |
| action_length = invocation_length + 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() |
| 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, actions, groups, prefix): |
| if prefix is None: |
| prefix = _('usage: ') |
| |
| # if usage is specified, use that |
| if usage is not None: |
| usage = usage % dict(prog=self._prog) |
| |
| # if no optionals or positionals are available, usage is just prog |
| elif usage is None and not actions: |
| usage = '%(prog)s' % dict(prog=self._prog) |
| |
| # if optionals and positionals are available, calculate usage |
| elif usage is None: |
| prog = '%(prog)s' % dict(prog=self._prog) |
| |
| # split optionals from positionals |
| optionals = [] |
| positionals = [] |
| for action in actions: |
| if action.option_strings: |
| optionals.append(action) |
| else: |
| positionals.append(action) |
| |
| # build full usage string |
| format = self._format_actions_usage |
| action_usage = format(optionals + positionals, groups) |
| usage = ' '.join([s for s in [prog, action_usage] if s]) |
| |
| # wrap the usage parts if it's too long |
| text_width = self._width - self._current_indent |
| if len(prefix) + len(usage) > text_width: |
| |
| # break usage into wrappable parts |
| part_regexp = r'\(.*?\)+|\[.*?\]+|\S+' |
| opt_usage = format(optionals, groups) |
| pos_usage = format(positionals, groups) |
| opt_parts = _re.findall(part_regexp, opt_usage) |
| pos_parts = _re.findall(part_regexp, pos_usage) |
| assert ' '.join(opt_parts) == opt_usage |
| assert ' '.join(pos_parts) == pos_usage |
| |
| # helper for wrapping lines |
| def get_lines(parts, indent, prefix=None): |
| lines = [] |
| line = [] |
| if prefix is not None: |
| line_len = len(prefix) - 1 |
| else: |
| line_len = len(indent) - 1 |
| for part in parts: |
| if line_len + 1 + len(part) > text_width and line: |
| lines.append(indent + ' '.join(line)) |
| line = [] |
| line_len = len(indent) - 1 |
| line.append(part) |
| line_len += len(part) + 1 |
| if line: |
| lines.append(indent + ' '.join(line)) |
| if prefix is not None: |
| lines[0] = lines[0][len(indent):] |
| return lines |
| |
| # if prog is short, follow it with optionals or positionals |
| if len(prefix) + len(prog) <= 0.75 * text_width: |
| indent = ' ' * (len(prefix) + len(prog) + 1) |
| if opt_parts: |
| lines = get_lines([prog] + opt_parts, indent, prefix) |
| lines.extend(get_lines(pos_parts, indent)) |
| elif pos_parts: |
| lines = get_lines([prog] + pos_parts, indent, prefix) |
| else: |
| lines = [prog] |
| |
| # if prog is long, put it on its own line |
| else: |
| indent = ' ' * len(prefix) |
| parts = opt_parts + pos_parts |
| lines = get_lines(parts, indent) |
| if len(lines) > 1: |
| lines = [] |
| lines.extend(get_lines(opt_parts, indent)) |
| lines.extend(get_lines(pos_parts, indent)) |
| lines = [prog] + lines |
| |
| # join lines into usage |
| usage = '\n'.join(lines) |
| |
| # prefix with 'usage:' |
| return '%s%s\n\n' % (prefix, usage) |
| |
| def _format_actions_usage(self, actions, groups): |
| # find group indices and identify actions in groups |
| group_actions = set() |
| inserts = {} |
| for group in groups: |
| try: |
| start = actions.index(group._group_actions[0]) |
| except ValueError: |
| continue |
| else: |
| end = start + len(group._group_actions) |
| if actions[start:end] == group._group_actions: |
| for action in group._group_actions: |
| group_actions.add(action) |
| if not group.required: |
| if start in inserts: |
| inserts[start] += ' [' |
| else: |
| inserts[start] = '[' |
| inserts[end] = ']' |
| else: |
| if start in inserts: |
| inserts[start] += ' (' |
| else: |
| inserts[start] = '(' |
| inserts[end] = ')' |
| for i in range(start + 1, end): |
| inserts[i] = '|' |
| |
| # collect all actions format strings |
| parts = [] |
| for i, action in enumerate(actions): |
| |
| # suppressed arguments are marked with None |
| # remove | separators for suppressed arguments |
| if action.help is SUPPRESS: |
| parts.append(None) |
| if inserts.get(i) == '|': |
| inserts.pop(i) |
| elif inserts.get(i + 1) == '|': |
| inserts.pop(i + 1) |
| |
| # produce all arg strings |
| elif not action.option_strings: |
| default = self._get_default_metavar_for_positional(action) |
| part = self._format_args(action, default) |
| |
| # if it's in a group, strip the outer [] |
| if action in group_actions: |
| if part[0] == '[' and part[-1] == ']': |
| part = part[1:-1] |
| |
| # add the action string to the list |
| parts.append(part) |
| |
| # 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 = self._get_default_metavar_for_optional(action) |
| args_string = self._format_args(action, default) |
| part = '%s %s' % (option_string, args_string) |
| |
| # make it look optional if it's not required or in a group |
| if not action.required and action not in group_actions: |
| part = '[%s]' % part |
| |
| # add the action string to the list |
| parts.append(part) |
| |
| # insert things at the necessary indices |
| for i in sorted(inserts, reverse=True): |
| parts[i:i] = [inserts[i]] |
| |
| # join all the action items with spaces |
| text = ' '.join([item for item in parts if item is not None]) |
| |
| # clean up separators for mutually exclusive groups |
| open = r'[\[(]' |
| close = r'[\])]' |
| text = _re.sub(r'(%s) ' % open, r'\1', text) |
| text = _re.sub(r' (%s)' % close, r'\1', text) |
| text = _re.sub(r'%s *%s' % (open, close), r'', text) |
| text = _re.sub(r'\(([^|]*)\)', r'\1', text) |
| text = text.strip() |
| |
| # return the text |
| return text |
| |
| def _format_text(self, text): |
| if '%(prog)' in text: |
| text = text % dict(prog=self._prog) |
| text_width = max(self._width - self._current_indent, 11) |
| 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 = max(self._width - help_position, 11) |
| action_width = help_position - self._current_indent - 2 |
| action_header = self._format_action_invocation(action) |
| |
| # no help; 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') |
| |
| # if there are any sub-actions, add their help as well |
| for subaction in self._iter_indented_subactions(action): |
| parts.append(self._format_action(subaction)) |
| |
| # return a single string |
| return self._join_parts(parts) |
| |
| def _format_action_invocation(self, action): |
| if not action.option_strings: |
| default = self._get_default_metavar_for_positional(action) |
| metavar, = self._metavar_formatter(action, default)(1) |
| return metavar |
| |
| 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 = self._get_default_metavar_for_optional(action) |
| 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 _metavar_formatter(self, action, default_metavar): |
| if action.metavar is not None: |
| result = action.metavar |
| elif action.choices is not None: |
| choice_strs = [str(choice) for choice in action.choices] |
| result = '{%s}' % ','.join(choice_strs) |
| else: |
| result = default_metavar |
| |
| def format(tuple_size): |
| if isinstance(result, tuple): |
| return result |
| else: |
| return (result, ) * tuple_size |
| return format |
| |
| def _format_args(self, action, default_metavar): |
| get_metavar = self._metavar_formatter(action, default_metavar) |
| if action.nargs is None: |
| result = '%s' % get_metavar(1) |
| elif action.nargs == OPTIONAL: |
| result = '[%s]' % get_metavar(1) |
| elif action.nargs == ZERO_OR_MORE: |
| result = '[%s [%s ...]]' % get_metavar(2) |
| elif action.nargs == ONE_OR_MORE: |
| result = '%s [%s ...]' % get_metavar(2) |
| elif action.nargs == REMAINDER: |
| result = '...' |
| elif action.nargs == PARSER: |
| result = '%s ...' % get_metavar(1) |
| else: |
| formats = ['%s' for _ in range(action.nargs)] |
| result = ' '.join(formats) % get_metavar(action.nargs) |
| return result |
| |
| def _expand_help(self, action): |
| params = dict(vars(action), prog=self._prog) |
| for name in list(params): |
| if params[name] is SUPPRESS: |
| del params[name] |
| for name in list(params): |
| if hasattr(params[name], '__name__'): |
| params[name] = params[name].__name__ |
| if params.get('choices') is not None: |
| choices_str = ', '.join([str(c) for c in params['choices']]) |
| params['choices'] = choices_str |
| return self._get_help_string(action) % params |
| |
| def _iter_indented_subactions(self, action): |
| try: |
| get_subactions = action._get_subactions |
| except AttributeError: |
| pass |
| else: |
| self._indent() |
| yield from get_subactions() |
| self._dedent() |
| |
| 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) |
| |
| def _get_help_string(self, action): |
| return action.help |
| |
| def _get_default_metavar_for_optional(self, action): |
| return action.dest.upper() |
| |
| def _get_default_metavar_for_positional(self, action): |
| return action.dest |
| |
| |
| class RawDescriptionHelpFormatter(HelpFormatter): |
| """Help message formatter which retains any formatting in descriptions. |
| |
| Only the name of this class is considered a public API. All the methods |
| provided by the class are considered an implementation detail. |
| """ |
| |
| def _fill_text(self, text, width, indent): |
| return ''.join(indent + line for line in text.splitlines(keepends=True)) |
| |
| |
| class RawTextHelpFormatter(RawDescriptionHelpFormatter): |
| """Help message formatter which retains formatting of all help text. |
| |
| Only the name of this class is considered a public API. All the methods |
| provided by the class are considered an implementation detail. |
| """ |
| |
| def _split_lines(self, text, width): |
| return text.splitlines() |
| |
| |
| class ArgumentDefaultsHelpFormatter(HelpFormatter): |
| """Help message formatter which adds default values to argument help. |
| |
| Only the name of this class is considered a public API. All the methods |
| provided by the class are considered an implementation detail. |
| """ |
| |
| def _get_help_string(self, action): |
| help = action.help |
| if '%(default)' not in action.help: |
| if action.default is not SUPPRESS: |
| defaulting_nargs = [OPTIONAL, ZERO_OR_MORE] |
| if action.option_strings or action.nargs in defaulting_nargs: |
| help += ' (default: %(default)s)' |
| return help |
| |
| |
| class MetavarTypeHelpFormatter(HelpFormatter): |
| """Help message formatter which uses the argument 'type' as the default |
| metavar value (instead of the argument 'dest') |
| |
| Only the name of this class is considered a public API. All the methods |
| provided by the class are considered an implementation detail. |
| """ |
| |
| def _get_default_metavar_for_optional(self, action): |
| return action.type.__name__ |
| |
| def _get_default_metavar_for_positional(self, action): |
| return action.type.__name__ |
| |
| |
| |
| # ===================== |
| # Options and Arguments |
| # ===================== |
| |
| def _get_action_name(argument): |
| if argument is None: |
| return None |
| elif argument.option_strings: |
| return '/'.join(argument.option_strings) |
| elif argument.metavar not in (None, SUPPRESS): |
| return argument.metavar |
| elif argument.dest not in (None, SUPPRESS): |
| return argument.dest |
| else: |
| return None |
| |
| |
| class ArgumentError(Exception): |
| """An error from 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): |
| self.argument_name = _get_action_name(argument) |
| 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) |
| |
| |
| class ArgumentTypeError(Exception): |
| """An error from trying to convert a command line string to a type.""" |
| pass |
| |
| |
| # ============== |
| # Action classes |
| # ============== |
| |
| class Action(_AttributeHolder): |
| """Information about how to convert command line strings to Python objects. |
| |
| Action objects are used by an ArgumentParser to represent the information |
| needed to parse a single argument from one or more strings from the |
| command line. The keyword arguments to the Action constructor are also |
| all attributes of Action instances. |
| |
| 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 -- A callable that accepts a single string argument, and |
| returns the converted value. The standard Python types str, int, |
| float, and complex are useful examples of such callables. If None, |
| str is used. |
| |
| - 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 for store actions must be > 0; if you ' |
| 'have nothing to store, actions such as store ' |
| 'true or store const may be more appropriate') |
| 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 for append actions must be > 0; if arg ' |
| 'strings are not supplying the value to append, ' |
| 'the append const action may be more appropriate') |
| 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): |
| items = _copy.copy(_ensure_value(namespace, self.dest, [])) |
| items.append(values) |
| setattr(namespace, self.dest, items) |
| |
| |
| 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): |
| items = _copy.copy(_ensure_value(namespace, self.dest, [])) |
| items.append(self.const) |
| setattr(namespace, self.dest, items) |
| |
| |
| 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=SUPPRESS, |
| default=SUPPRESS, |
| help=None): |
| super(_HelpAction, self).__init__( |
| option_strings=option_strings, |
| dest=dest, |
| default=default, |
| 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, |
| version=None, |
| dest=SUPPRESS, |
| default=SUPPRESS, |
| help="show program's version number and exit"): |
| super(_VersionAction, self).__init__( |
| option_strings=option_strings, |
| dest=dest, |
| default=default, |
| nargs=0, |
| help=help) |
| self.version = version |
| |
| def __call__(self, parser, namespace, values, option_string=None): |
| version = self.version |
| if version is None: |
| version = parser.version |
| formatter = parser._get_formatter() |
| formatter.add_text(version) |
| parser._print_message(formatter.format_help(), _sys.stdout) |
| parser.exit() |
| |
| |
| class _SubParsersAction(Action): |
| |
| class _ChoicesPseudoAction(Action): |
| |
| def __init__(self, name, aliases, help): |
| metavar = dest = name |
| if aliases: |
| metavar += ' (%s)' % ', '.join(aliases) |
| sup = super(_SubParsersAction._ChoicesPseudoAction, self) |
| sup.__init__(option_strings=[], dest=dest, help=help, |
| metavar=metavar) |
| |
| 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 = _collections.OrderedDict() |
| self._choices_actions = [] |
| |
| 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): |
| # set prog from the existing prefix |
| if kwargs.get('prog') is None: |
| kwargs['prog'] = '%s %s' % (self._prog_prefix, name) |
| |
| aliases = kwargs.pop('aliases', ()) |
| |
| # create a pseudo-action to hold the choice help |
| if 'help' in kwargs: |
| help = kwargs.pop('help') |
| choice_action = self._ChoicesPseudoAction(name, aliases, help) |
| self._choices_actions.append(choice_action) |
| |
| # create the parser and add it to the map |
| parser = self._parser_class(**kwargs) |
| self._name_parser_map[name] = parser |
| |
| # make parser available under aliases also |
| for alias in aliases: |
| self._name_parser_map[alias] = parser |
| |
| return parser |
| |
| def _get_subactions(self): |
| return self._choices_actions |
| |
| 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: |
| args = {'parser_name': parser_name, |
| 'choices': ', '.join(self._name_parser_map)} |
| msg = _('unknown parser %(parser_name)r (choices: %(choices)s)') % args |
| raise ArgumentError(self, msg) |
| |
| # parse all the remaining options into the namespace |
| # store any unrecognized options on the object, so that the top |
| # level parser can decide what to do with them |
| |
| # In case this subparser defines new defaults, we parse them |
| # in a new namespace object and then update the original |
| # namespace for the relevant parts. |
| subnamespace, arg_strings = parser.parse_known_args(arg_strings, None) |
| for key, value in vars(subnamespace).items(): |
| setattr(namespace, key, value) |
| |
| if arg_strings: |
| vars(namespace).setdefault(_UNRECOGNIZED_ARGS_ATTR, []) |
| getattr(namespace, _UNRECOGNIZED_ARGS_ATTR).extend(arg_strings) |
| |
| |
| # ============== |
| # 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. |
| - encoding -- The file's encoding. Accepts the same values as the |
| builtin open() function. |
| - errors -- A string indicating how encoding and decoding errors are to |
| be handled. Accepts the same value as the builtin open() function. |
| """ |
| |
| def __init__(self, mode='r', bufsize=-1, encoding=None, errors=None): |
| self._mode = mode |
| self._bufsize = bufsize |
| self._encoding = encoding |
| self._errors = errors |
| |
| def __call__(self, string): |
| # the special argument "-" means sys.std{in,out} |
| if string == '-': |
| if 'r' in self._mode: |
| return _sys.stdin |
| elif 'w' in self._mode: |
| return _sys.stdout |
| else: |
| msg = _('argument "-" with mode %r') % self._mode |
| raise ValueError(msg) |
| |
| # all other arguments are used as file names |
| try: |
| return open(string, self._mode, self._bufsize, self._encoding, |
| self._errors) |
| except OSError as e: |
| message = _("can't open '%s': %s") |
| raise ArgumentTypeError(message % (string, e)) |
| |
| def __repr__(self): |
| args = self._mode, self._bufsize |
| kwargs = [('encoding', self._encoding), ('errors', self._errors)] |
| args_str = ', '.join([repr(arg) for arg in args if arg != -1] + |
| ['%s=%r' % (kw, arg) for kw, arg in kwargs |
| if arg is not None]) |
| return '%s(%s)' % (type(self).__name__, args_str) |
| |
| # =========================== |
| # Optional and Positional Parsing |
| # =========================== |
| |
| class Namespace(_AttributeHolder): |
| """Simple object for storing attributes. |
| |
| Implements equality by attribute names and values, and provides a simple |
| string representation. |
| """ |
| |
| def __init__(self, **kwargs): |
| for name in kwargs: |
| setattr(self, name, kwargs[name]) |
| |
| def __eq__(self, other): |
| if not isinstance(other, Namespace): |
| return NotImplemented |
| return vars(self) == vars(other) |
| |
| def __ne__(self, other): |
| if not isinstance(other, Namespace): |
| return NotImplemented |
| return not (self == other) |
| |
| def __contains__(self, key): |
| return key in self.__dict__ |
| |
| |
| class _ActionsContainer(object): |
| |
| def __init__(self, |
| description, |
| prefix_chars, |
| argument_default, |
| conflict_handler): |
| super(_ActionsContainer, self).__init__() |
| |
| self.description = description |
| self.argument_default = argument_default |
| self.prefix_chars = prefix_chars |
| 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._actions = [] |
| self._option_string_actions = {} |
| |
| # groups |
| self._action_groups = [] |
| self._mutually_exclusive_groups = [] |
| |
| # defaults storage |
| self._defaults = {} |
| |
| # determines whether an "option" looks like a negative number |
| self._negative_number_matcher = _re.compile(r'^-\d+$|^-\d*\.\d+$') |
| |
| # whether or not there are any optionals that look like negative |
| # numbers -- uses a list so it can be shared and edited |
| self._has_negative_number_optionals = [] |
| |
| # ==================== |
| # 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) |
| |
| # ================================== |
| # Namespace default accessor methods |
| # ================================== |
| def set_defaults(self, **kwargs): |
| self._defaults.update(kwargs) |
| |
| # if these defaults match any existing arguments, replace |
| # the previous default on the object with the new one |
| for action in self._actions: |
| if action.dest in kwargs: |
| action.default = kwargs[action.dest] |
| |
| def get_default(self, dest): |
| for action in self._actions: |
| if action.dest == dest and action.default is not None: |
| return action.default |
| return self._defaults.get(dest, None) |
| |
| |
| # ======================= |
| # Adding argument actions |
| # ======================= |
| def add_argument(self, *args, **kwargs): |
| """ |
| add_argument(dest, ..., name=value, ...) |
| add_argument(option_string, option_string, ..., name=value, ...) |
| """ |
| |
| # if no positional args are supplied or only one is supplied and |
| # it doesn't look like an option string, parse a positional |
| # argument |
| chars = self.prefix_chars |
| if not args or len(args) == 1 and args[0][0] not in chars: |
| if args and 'dest' in kwargs: |
| raise ValueError('dest supplied twice for positional argument') |
| kwargs = self._get_positional_kwargs(*args, **kwargs) |
| |
| # otherwise, we're adding an optional argument |
| else: |
| kwargs = self._get_optional_kwargs(*args, **kwargs) |
| |
| # if no default was supplied, use the parser-level default |
| if 'default' not in kwargs: |
| dest = kwargs['dest'] |
| if dest in self._defaults: |
| kwargs['default'] = self._defaults[dest] |
| elif self.argument_default is not None: |
| kwargs['default'] = self.argument_default |
| |
| # create the action object, and add it to the parser |
| action_class = self._pop_action_class(kwargs) |
| if not callable(action_class): |
| raise ValueError('unknown action "%s"' % (action_class,)) |
| action = action_class(**kwargs) |
| |
| # raise an error if the action type is not callable |
| type_func = self._registry_get('type', action.type, action.type) |
| if not callable(type_func): |
| raise ValueError('%r is not callable' % (type_func,)) |
| |
| # raise an error if the metavar does not match the type |
| if hasattr(self, "_get_formatter"): |
| try: |
| self._get_formatter()._format_args(action, None) |
| except TypeError: |
| raise ValueError("length of metavar tuple does not match nargs") |
| |
| return self._add_action(action) |
| |
| def add_argument_group(self, *args, **kwargs): |
| group = _ArgumentGroup(self, *args, **kwargs) |
| self._action_groups.append(group) |
| return group |
| |
| def add_mutually_exclusive_group(self, **kwargs): |
| group = _MutuallyExclusiveGroup(self, **kwargs) |
| self._mutually_exclusive_groups.append(group) |
| return group |
| |
| def _add_action(self, action): |
| # resolve any conflicts |
| self._check_conflict(action) |
| |
| # add to actions list |
| self._actions.append(action) |
| action.container = self |
| |
| # index the action by any option strings it has |
| for option_string in action.option_strings: |
| self._option_string_actions[option_string] = action |
| |
| # set the flag if any option strings look like negative numbers |
| for option_string in action.option_strings: |
| if self._negative_number_matcher.match(option_string): |
| if not self._has_negative_number_optionals: |
| self._has_negative_number_optionals.append(True) |
| |
| # return the created action |
| return action |
| |
| def _remove_action(self, action): |
| self._actions.remove(action) |
| |
| def _add_container_actions(self, container): |
| # collect groups by titles |
| title_group_map = {} |
| for group in self._action_groups: |
| if group.title in title_group_map: |
| msg = _('cannot merge actions - two groups are named %r') |
| raise ValueError(msg % (group.title)) |
| title_group_map[group.title] = group |
| |
| # map each action to its group |
| group_map = {} |
| for group in container._action_groups: |
| |
| # if a group with the title exists, use that, otherwise |
| # create a new group matching the container's group |
| if group.title not in title_group_map: |
| title_group_map[group.title] = self.add_argument_group( |
| title=group.title, |
| description=group.description, |
| conflict_handler=group.conflict_handler) |
| |
| # map the actions to their new group |
| for action in group._group_actions: |
| group_map[action] = title_group_map[group.title] |
| |
| # add container's mutually exclusive groups |
| # NOTE: if add_mutually_exclusive_group ever gains title= and |
| # description= then this code will need to be expanded as above |
| for group in container._mutually_exclusive_groups: |
| mutex_group = self.add_mutually_exclusive_group( |
| required=group.required) |
| |
| # map the actions to their new mutex group |
| for action in group._group_actions: |
| group_map[action] = mutex_group |
| |
| # add all actions to this container or their group |
| for action in container._actions: |
| group_map.get(action, 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) |
| |
| # mark positional arguments as required if at least one is |
| # always required |
| if kwargs.get('nargs') not in [OPTIONAL, ZERO_OR_MORE]: |
| kwargs['required'] = True |
| if kwargs.get('nargs') == ZERO_OR_MORE and 'default' not in kwargs: |
| kwargs['required'] = True |
| |
| # 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 strings that don't start with an appropriate prefix |
| if not option_string[0] in self.prefix_chars: |
| args = {'option': option_string, |
| 'prefix_chars': self.prefix_chars} |
| msg = _('invalid option string %(option)r: ' |
| 'must start with a character %(prefix_chars)r') |
| raise ValueError(msg % args) |
| |
| # strings starting with two prefix characters are long options |
| option_strings.append(option_string) |
| if option_string[0] in self.prefix_chars: |
| if len(option_string) > 1: |
| if option_string[1] in self.prefix_chars: |
| 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(self.prefix_chars) |
| if not dest: |
| msg = _('dest= is required for options like %r') |
| raise ValueError(msg % option_string) |
| dest = dest.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_string_actions: |
| confl_optional = self._option_string_actions[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 = ngettext('conflicting option string: %s', |
| 'conflicting option strings: %s', |
| len(conflicting_actions)) |
| 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_string_actions.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._remove_action(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) |
| update('prefix_chars', container.prefix_chars) |
| update('argument_default', container.argument_default) |
| super_init = super(_ArgumentGroup, self).__init__ |
| super_init(description=description, **kwargs) |
| |
| # group attributes |
| self.title = title |
| self._group_actions = [] |
| |
| # share most attributes with the container |
| self._registries = container._registries |
| self._actions = container._actions |
| self._option_string_actions = container._option_string_actions |
| self._defaults = container._defaults |
| self._has_negative_number_optionals = \ |
| container._has_negative_number_optionals |
| self._mutually_exclusive_groups = container._mutually_exclusive_groups |
| |
| def _add_action(self, action): |
| action = super(_ArgumentGroup, self)._add_action(action) |
| self._group_actions.append(action) |
| return action |
| |
| def _remove_action(self, action): |
| super(_ArgumentGroup, self)._remove_action(action) |
| self._group_actions.remove(action) |
| |
| |
| class _MutuallyExclusiveGroup(_ArgumentGroup): |
| |
| def __init__(self, container, required=False): |
| super(_MutuallyExclusiveGroup, self).__init__(container) |
| self.required = required |
| self._container = container |
| |
| def _add_action(self, action): |
| if action.required: |
| msg = _('mutually exclusive arguments must be optional') |
| raise ValueError(msg) |
| action = self._container._add_action(action) |
| self._group_actions.append(action) |
| return action |
| |
| def _remove_action(self, action): |
| self._container._remove_action(action) |
| self._group_actions.remove(action) |
| |
| |
| class ArgumentParser(_AttributeHolder, _ActionsContainer): |
| """Object for parsing command line strings into Python objects. |
| |
| Keyword Arguments: |
| - prog -- The name of the program (default: sys.argv[0]) |
| - usage -- A usage message (default: auto-generated from arguments) |
| - description -- A description of what the program does |
| - epilog -- Text following the argument descriptions |
| - parents -- Parsers whose arguments should be copied into this one |
| - formatter_class -- HelpFormatter class for printing help messages |
| - prefix_chars -- Characters that prefix optional arguments |
| - fromfile_prefix_chars -- Characters that prefix files containing |
| additional arguments |
| - argument_default -- The default value for all arguments |
| - conflict_handler -- String indicating how to handle conflicts |
| - add_help -- Add a -h/-help option |
| """ |
| |
| def __init__(self, |
| prog=None, |
| usage=None, |
| description=None, |
| epilog=None, |
| parents=[], |
| formatter_class=HelpFormatter, |
| prefix_chars='-', |
| fromfile_prefix_chars=None, |
| argument_default=None, |
| conflict_handler='error', |
| add_help=True): |
| |
| superinit = super(ArgumentParser, self).__init__ |
| superinit(description=description, |
| prefix_chars=prefix_chars, |
| argument_default=argument_default, |
| 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.formatter_class = formatter_class |
| self.fromfile_prefix_chars = fromfile_prefix_chars |
| self.add_help = add_help |
| |
| add_group = self.add_argument_group |
| self._positionals = add_group(_('positional arguments')) |
| self._optionals = add_group(_('optional arguments')) |
| self._subparsers = None |
| |
| # register types |
| def identity(string): |
| return string |
| self.register('type', None, identity) |
| |
| # add help argument if necessary |
| # (using explicit default to override global argument_default) |
| default_prefix = '-' if '-' in prefix_chars else prefix_chars[0] |
| if self.add_help: |
| self.add_argument( |
| default_prefix+'h', default_prefix*2+'help', |
| action='help', default=SUPPRESS, |
| help=_('show this help message and exit')) |
| |
| # 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) |
| |
| # ======================= |
| # Pretty __repr__ methods |
| # ======================= |
| def _get_kwargs(self): |
| names = [ |
| 'prog', |
| 'usage', |
| 'description', |
| 'formatter_class', |
| 'conflict_handler', |
| 'add_help', |
| ] |
| return [(name, getattr(self, name)) for name in names] |
| |
| # ================================== |
| # Optional/Positional adding methods |
| # ================================== |
| def add_subparsers(self, **kwargs): |
| if self._subparsers is not None: |
| 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)) |
| |
| if 'title' in kwargs or 'description' in kwargs: |
| title = _(kwargs.pop('title', 'subcommands')) |
| description = _(kwargs.pop('description', None)) |
| self._subparsers = self.add_argument_group(title, description) |
| else: |
| self._subparsers = self._positionals |
| |
| # 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() |
| positionals = self._get_positional_actions() |
| groups = self._mutually_exclusive_groups |
| formatter.add_usage(self.usage, positionals, groups, '') |
| 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._subparsers._add_action(action) |
| |
| # return the created parsers action |
| return action |
| |
| def _add_action(self, action): |
| if action.option_strings: |
| self._optionals._add_action(action) |
| else: |
| self._positionals._add_action(action) |
| return action |
| |
| def _get_optional_actions(self): |
| return [action |
| for action in self._actions |
| if action.option_strings] |
| |
| def _get_positional_actions(self): |
| return [action |
| for action in self._actions |
| if not action.option_strings] |
| |
| # ===================================== |
| # Command line argument parsing methods |
| # ===================================== |
| def parse_args(self, args=None, namespace=None): |
| args, argv = self.parse_known_args(args, namespace) |
| if argv: |
| msg = _('unrecognized arguments: %s') |
| self.error(msg % ' '.join(argv)) |
| return args |
| |
| def parse_known_args(self, args=None, namespace=None): |
| if args is None: |
| # args default to the system args |
| args = _sys.argv[1:] |
| else: |
| # make sure that args are mutable |
| args = list(args) |
| |
| # default Namespace built from parser defaults |
| if namespace is None: |
| namespace = Namespace() |
| |
| # add any action defaults that aren't present |
| for action in self._actions: |
| if action.dest is not SUPPRESS: |
| if not hasattr(namespace, action.dest): |
| if action.default is not SUPPRESS: |
| setattr(namespace, action.dest, action.default) |
| |
| # add any parser defaults that aren't present |
| for dest in self._defaults: |
| if not hasattr(namespace, dest): |
| setattr(namespace, dest, self._defaults[dest]) |
| |
| # parse the arguments and exit if there are any errors |
| try: |
| namespace, args = self._parse_known_args(args, namespace) |
| if hasattr(namespace, _UNRECOGNIZED_ARGS_ATTR): |
| args.extend(getattr(namespace, _UNRECOGNIZED_ARGS_ATTR)) |
| delattr(namespace, _UNRECOGNIZED_ARGS_ATTR) |
| return namespace, args |
| except ArgumentError: |
| err = _sys.exc_info()[1] |
| self.error(str(err)) |
| |
| def _parse_known_args(self, arg_strings, namespace): |
| # replace arg strings that are file references |
| if self.fromfile_prefix_chars is not None: |
| arg_strings = self._read_args_from_files(arg_strings) |
| |
| # map all mutually exclusive arguments to the other arguments |
| # they can't occur with |
| action_conflicts = {} |
| for mutex_group in self._mutually_exclusive_groups: |
| group_actions = mutex_group._group_actions |
| for i, mutex_action in enumerate(mutex_group._group_actions): |
| conflicts = action_conflicts.setdefault(mutex_action, []) |
| conflicts.extend(group_actions[:i]) |
| conflicts.extend(group_actions[i + 1:]) |
| |
| # 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 |
| seen_actions = set() |
| seen_non_default_actions = set() |
| |
| def take_action(action, argument_strings, option_string=None): |
| seen_actions.add(action) |
| argument_values = self._get_values(action, argument_strings) |
| |
| # error if this argument is not allowed with other previously |
| # seen arguments, assuming that actions that use the default |
| # value don't really count as "present" |
| if argument_values is not action.default: |
| seen_non_default_actions.add(action) |
| for conflict_action in action_conflicts.get(action, []): |
| if conflict_action in seen_non_default_actions: |
| msg = _('not allowed with argument %s') |
| action_name = _get_action_name(conflict_action) |
| raise ArgumentError(action, msg % action_name) |
| |
| # take the action if we didn't receive a SUPPRESS value |
| # (e.g. from a default) |
| if argument_values is not SUPPRESS: |
| action(self, namespace, argument_values, option_string) |
| |
| # function to convert arg_strings into an optional action |
| def consume_optional(start_index): |
| |
| # get the optional identified at this index |
| option_tuple = option_string_indices[start_index] |
| action, option_string, explicit_arg = option_tuple |
| |
| # identify additional optionals in the same arg string |
| # (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, skip it |
| if action is None: |
| extras.append(arg_strings[start_index]) |
| return start_index + 1 |
| |
| # 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 |
| chars = self.prefix_chars |
| if arg_count == 0 and option_string[1] not in chars: |
| action_tuples.append((action, [], option_string)) |
| char = option_string[0] |
| option_string = char + explicit_arg[0] |
| new_explicit_arg = explicit_arg[1:] or None |
| optionals_map = self._option_string_actions |
| if option_string in optionals_map: |
| action = optionals_map[option_string] |
| explicit_arg = new_explicit_arg |
| else: |
| msg = _('ignored explicit argument %r') |
| raise ArgumentError(action, msg % explicit_arg) |
| |
| # 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 |
| extras = [] |
| 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 extra arguments |
| if start_index not in option_string_indices: |
| strings = arg_strings[start_index:next_option_string_index] |
| extras.extend(strings) |
| start_index = next_option_string_index |
| |
| # 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 extras |
| extras.extend(arg_strings[stop_index:]) |
| |
| # make sure all required actions were present and also convert |
| # action defaults which were not given as arguments |
| required_actions = [] |
| for action in self._actions: |
| if action not in seen_actions: |
| if action.required: |
| required_actions.append(_get_action_name(action)) |
| else: |
| # Convert action default now instead of doing it before |
| # parsing arguments to avoid calling convert functions |
| # twice (which may fail) if the argument was given, but |
| # only if it was defined already in the namespace |
| if (action.default is not None and |
| isinstance(action.default, str) and |
| hasattr(namespace, action.dest) and |
| action.default is getattr(namespace, action.dest)): |
| setattr(namespace, action.dest, |
| self._get_value(action, action.default)) |
| |
| if required_actions: |
| self.error(_('the following arguments are required: %s') % |
| ', '.join(required_actions)) |
| |
| # make sure all required groups had one option present |
| for group in self._mutually_exclusive_groups: |
| if group.required: |
| for action in group._group_actions: |
| if action in seen_non_default_actions: |
| break |
| |
| # if no actions were used, report the error |
| else: |
| names = [_get_action_name(action) |
| for action in group._group_actions |
| if action.help is not SUPPRESS] |
| msg = _('one of the arguments %s is required') |
| self.error(msg % ' '.join(names)) |
| |
| # return the updated namespace and the extra arguments |
| return namespace, extras |
| |
| def _read_args_from_files(self, arg_strings): |
| # expand arguments referencing files |
| new_arg_strings = [] |
| for arg_string in arg_strings: |
| |
| # for regular arguments, just add them back into the list |
| if not arg_string or arg_string[0] not in self.fromfile_prefix_chars: |
| new_arg_strings.append(arg_string) |
| |
| # replace arguments referencing files with the file content |
| else: |
| try: |
| with open(arg_string[1:]) as args_file: |
| arg_strings = [] |
| for arg_line in args_file.read().splitlines(): |
| for arg in self.convert_arg_line_to_args(arg_line): |
| arg_strings.append(arg) |
| arg_strings = self._read_args_from_files(arg_strings) |
| new_arg_strings.extend(arg_strings) |
| except OSError: |
| err = _sys.exc_info()[1] |
| self.error(str(err)) |
| |
| # return the modified argument list |
| return new_arg_strings |
| |
| def convert_arg_line_to_args(self, arg_line): |
| return [arg_line] |
| |
| 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 = ngettext('expected %s argument', |
| 'expected %s arguments', |
| action.nargs) % 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 range(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's an empty string, it was meant to be a positional |
| if not arg_string: |
| return None |
| |
| # if it doesn't start with a prefix, it was meant to be positional |
| if not arg_string[0] in self.prefix_chars: |
| return None |
| |
| # if the option string is present in the parser, return the action |
| if arg_string in self._option_string_actions: |
| action = self._option_string_actions[arg_string] |
| return action, arg_string, None |
| |
| # if it's just a single character, it was meant to be positional |
| if len(arg_string) == 1: |
| return None |
| |
| # if the option string before the "=" is present, return the action |
| if '=' in arg_string: |
| option_string, explicit_arg = arg_string.split('=', 1) |
| if option_string in self._option_string_actions: |
| action = self._option_string_actions[option_string] |
| return action, option_string, explicit_arg |
| |
| # search through all possible prefixes of the option string |
| # and all actions in the parser for possible interpretations |
| option_tuples = self._get_option_tuples(arg_string) |
| |
| # if multiple actions match, the option string was ambiguous |
| if len(option_tuples) > 1: |
| options = ', '.join([option_string |
| for action, option_string, explicit_arg in option_tuples]) |
| args = {'option': arg_string, 'matches': options} |
| msg = _('ambiguous option: %(option)s could match %(matches)s') |
| self.error(msg % args) |
| |
| # 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 |
| # unless there are negative-number-like options |
| if self._negative_number_matcher.match(arg_string): |
| if not self._has_negative_number_optionals: |
| return None |
| |
| # if it contains a space, it was meant to be a positional |
| if ' ' in 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_tuples(self, option_string): |
| result = [] |
| |
| # option strings starting with two prefix characters are only |
| # split at the '=' |
| chars = self.prefix_chars |
| if option_string[0] in chars and option_string[1] in chars: |
| if '=' in option_string: |
| option_prefix, explicit_arg = option_string.split('=', 1) |
| else: |
| option_prefix = option_string |
| explicit_arg = None |
| for option_string in self._option_string_actions: |
| if option_string.startswith(option_prefix): |
| action = self._option_string_actions[option_string] |
| tup = action, option_string, explicit_arg |
| result.append(tup) |
| |
| # single character options can be concatenated with their arguments |
| # but multiple character options always have to have their argument |
| # separate |
| elif option_string[0] in chars and option_string[1] not in chars: |
| option_prefix = option_string |
| explicit_arg = None |
| short_option_prefix = option_string[:2] |
| short_explicit_arg = option_string[2:] |
| |
| for option_string in self._option_string_actions: |
| if option_string == short_option_prefix: |
| action = self._option_string_actions[option_string] |
| tup = action, option_string, short_explicit_arg |
| result.append(tup) |
| elif option_string.startswith(option_prefix): |
| action = self._option_string_actions[option_string] |
| tup = action, option_string, explicit_arg |
| result.append(tup) |
| |
| # shouldn't ever get here |
| else: |
| self.error(_('unexpected option string: %s') % option_string) |
| |
| # return the collected option 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 any number of options or arguments |
| elif nargs == REMAINDER: |
| nargs_pattern = '([-AO]*)' |
| |
| # allow one argument followed by any number of options or arguments |
| elif nargs == 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, REMAINDER args, strip out first '--' |
| if action.nargs not in [PARSER, REMAINDER]: |
| try: |
| arg_strings.remove('--') |
| except ValueError: |
| pass |
| |
| # 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, str): |
| 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) |
| |
| # REMAINDER arguments convert all values, checking none |
| elif action.nargs == REMAINDER: |
| value = [self._get_value(action, v) for v in arg_strings] |
| |
| # PARSER arguments convert all values, but check only the first |
| elif action.nargs == PARSER: |
| value = [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 = [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) |
| |
| # ArgumentTypeErrors indicate errors |
| except ArgumentTypeError: |
| name = getattr(action.type, '__name__', repr(action.type)) |
| msg = str(_sys.exc_info()[1]) |
| raise ArgumentError(action, msg) |
| |
| # TypeErrors or ValueErrors also indicate errors |
| except (TypeError, ValueError): |
| name = getattr(action.type, '__name__', repr(action.type)) |
| args = {'type': name, 'value': arg_string} |
| msg = _('invalid %(type)s value: %(value)r') |
| raise ArgumentError(action, msg % args) |
| |
| # 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: |
| args = {'value': value, |
| 'choices': ', '.join(map(repr, action.choices))} |
| msg = _('invalid choice: %(value)r (choose from %(choices)s)') |
| raise ArgumentError(action, msg % args) |
| |
| # ======================= |
| # Help-formatting methods |
| # ======================= |
| def format_usage(self): |
| formatter = self._get_formatter() |
| formatter.add_usage(self.usage, self._actions, |
| self._mutually_exclusive_groups) |
| return formatter.format_help() |
| |
| def format_help(self): |
| formatter = self._get_formatter() |
| |
| # usage |
| formatter.add_usage(self.usage, self._actions, |
| self._mutually_exclusive_groups) |
| |
| # description |
| formatter.add_text(self.description) |
| |
| # positionals, optionals and user-defined groups |
| for action_group in self._action_groups: |
| formatter.start_section(action_group.title) |
| formatter.add_text(action_group.description) |
| formatter.add_arguments(action_group._group_actions) |
| formatter.end_section() |
| |
| # epilog |
| formatter.add_text(self.epilog) |
| |
| # determine help from format above |
| return formatter.format_help() |
| |
| def _get_formatter(self): |
| return self.formatter_class(prog=self.prog) |
| |
| # ===================== |
| # Help-printing methods |
| # ===================== |
| def print_usage(self, file=None): |
| if file is None: |
| file = _sys.stdout |
| self._print_message(self.format_usage(), file) |
| |
| def print_help(self, file=None): |
| if file is None: |
| file = _sys.stdout |
| self._print_message(self.format_help(), 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: |
| self._print_message(message, _sys.stderr) |
| _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) |
| args = {'prog': self.prog, 'message': message} |
| self.exit(2, _('%(prog)s: error: %(message)s\n') % args) |