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1# Copyright 2012-2023, Andrey Kislyuk and argcomplete contributors. Licensed under the terms of the
2# `Apache License, Version 2.0 <http://www.apache.org/licenses/LICENSE-2.0>`_. Distribution of the LICENSE and NOTICE
3# files with source copies of this package and derivative works is **REQUIRED** as specified by the Apache License.
4# See https://github.com/kislyuk/argcomplete for more info.
6# This file contains argparse introspection utilities used in the course of argcomplete execution.
8from argparse import (
9 ONE_OR_MORE,
10 OPTIONAL,
11 PARSER,
12 REMAINDER,
13 SUPPRESS,
14 ZERO_OR_MORE,
15 Action,
16 ArgumentError,
17 ArgumentParser,
18 _get_action_name,
19 _SubParsersAction,
20)
21from gettext import gettext
22from typing import Dict, List, Set, Tuple
24_num_consumed_args: Dict[Action, int] = {}
27def action_is_satisfied(action):
28 '''Returns False if the parse would raise an error if no more arguments are given to this action, True otherwise.'''
29 num_consumed_args = _num_consumed_args.get(action, 0)
31 if action.nargs in [OPTIONAL, ZERO_OR_MORE, REMAINDER]:
32 return True
33 if action.nargs == ONE_OR_MORE:
34 return num_consumed_args >= 1
35 if action.nargs == PARSER:
36 # Not sure what this should be, but this previously always returned False
37 # so at least this won't break anything that wasn't already broken.
38 return False
39 if action.nargs is None:
40 return num_consumed_args == 1
42 assert isinstance(action.nargs, int), 'failed to handle a possible nargs value: %r' % action.nargs
43 return num_consumed_args == action.nargs
46def action_is_open(action):
47 '''Returns True if action could consume more arguments (i.e., its pattern is open).'''
48 num_consumed_args = _num_consumed_args.get(action, 0)
50 if action.nargs in [ZERO_OR_MORE, ONE_OR_MORE, PARSER, REMAINDER]:
51 return True
52 if action.nargs == OPTIONAL or action.nargs is None:
53 return num_consumed_args == 0
55 assert isinstance(action.nargs, int), 'failed to handle a possible nargs value: %r' % action.nargs
56 return num_consumed_args < action.nargs
59def action_is_greedy(action, isoptional=False):
60 '''Returns True if action will necessarily consume the next argument.
61 isoptional indicates whether the argument is an optional (starts with -).
62 '''
63 num_consumed_args = _num_consumed_args.get(action, 0)
65 if action.option_strings:
66 if not isoptional and not action_is_satisfied(action):
67 return True
68 return action.nargs == REMAINDER
69 else:
70 return action.nargs == REMAINDER and num_consumed_args >= 1
73class IntrospectiveArgumentParser(ArgumentParser):
74 '''The following is a verbatim copy of ArgumentParser._parse_known_args (Python 2.7.3),
75 except for the lines that contain the string "Added by argcomplete".
76 '''
78 def _parse_known_args(self, arg_strings, namespace, intermixed=False, **kwargs):
79 _num_consumed_args.clear() # Added by argcomplete
80 self._argcomplete_namespace = namespace
81 self.active_actions: List[Action] = [] # Added by argcomplete
82 # replace arg strings that are file references
83 if self.fromfile_prefix_chars is not None:
84 arg_strings = self._read_args_from_files(arg_strings)
86 # map all mutually exclusive arguments to the other arguments
87 # they can't occur with
88 action_conflicts: Dict[Action, List[Action]] = {}
89 self._action_conflicts = action_conflicts # Added by argcomplete
90 for mutex_group in self._mutually_exclusive_groups:
91 group_actions = mutex_group._group_actions
92 for i, mutex_action in enumerate(mutex_group._group_actions):
93 conflicts = action_conflicts.setdefault(mutex_action, [])
94 conflicts.extend(group_actions[:i])
95 conflicts.extend(group_actions[i + 1 :])
97 # find all option indices, and determine the arg_string_pattern
98 # which has an 'O' if there is an option at an index,
99 # an 'A' if there is an argument, or a '-' if there is a '--'
100 option_string_indices = {}
101 arg_string_pattern_parts = []
102 arg_strings_iter = iter(arg_strings)
103 for i, arg_string in enumerate(arg_strings_iter):
104 # all args after -- are non-options
105 if arg_string == '--':
106 arg_string_pattern_parts.append('-')
107 for arg_string in arg_strings_iter:
108 arg_string_pattern_parts.append('A')
110 # otherwise, add the arg to the arg strings
111 # and note the index if it was an option
112 else:
113 option_tuple = self._parse_optional(arg_string)
114 if option_tuple is None:
115 pattern = 'A'
116 else:
117 option_string_indices[i] = option_tuple
118 pattern = 'O'
119 arg_string_pattern_parts.append(pattern)
121 # join the pieces together to form the pattern
122 arg_strings_pattern = ''.join(arg_string_pattern_parts)
124 # converts arg strings to the appropriate and then takes the action
125 seen_actions: Set[Action] = set()
126 seen_non_default_actions: Set[Action] = set()
127 self._seen_non_default_actions = seen_non_default_actions # Added by argcomplete
129 def take_action(action, argument_strings, option_string=None):
130 seen_actions.add(action)
131 argument_values = self._get_values(action, argument_strings)
133 # error if this argument is not allowed with other previously
134 # seen arguments, assuming that actions that use the default
135 # value don't really count as "present"
136 if argument_values is not action.default:
137 seen_non_default_actions.add(action)
138 for conflict_action in action_conflicts.get(action, []):
139 if conflict_action in seen_non_default_actions:
140 msg = gettext('not allowed with argument %s')
141 action_name = _get_action_name(conflict_action)
142 raise ArgumentError(action, msg % action_name)
144 # take the action if we didn't receive a SUPPRESS value
145 # (e.g. from a default)
146 if argument_values is not SUPPRESS or isinstance(action, _SubParsersAction):
147 try:
148 action(self, namespace, argument_values, option_string)
149 except BaseException:
150 # Begin added by argcomplete
151 # When a subparser action is taken and fails due to incomplete arguments, it does not merge the
152 # contents of its parsed namespace into the parent namespace. Do that here to allow completers to
153 # access the partially parsed arguments for the subparser.
154 if isinstance(action, _SubParsersAction):
155 subnamespace = action._name_parser_map[argument_values[0]]._argcomplete_namespace
156 for key, value in vars(subnamespace).items():
157 setattr(namespace, key, value)
158 # End added by argcomplete
159 raise
161 # function to convert arg_strings into an optional action
162 def consume_optional(start_index):
163 # get the optional identified at this index
164 option_tuple = option_string_indices[start_index]
165 if isinstance(option_tuple, list): # Python 3.12.7+
166 option_tuple = option_tuple[0]
167 if len(option_tuple) == 3:
168 action, option_string, explicit_arg = option_tuple
169 else: # Python 3.11.9+, 3.12.3+, 3.13+
170 action, option_string, _, explicit_arg = option_tuple
172 # identify additional optionals in the same arg string
173 # (e.g. -xyz is the same as -x -y -z if no args are required)
174 match_argument = self._match_argument
175 action_tuples: List[Tuple[Action, List[str], str]] = []
176 while True:
177 # if we found no optional action, skip it
178 if action is None:
179 extras.append(arg_strings[start_index])
180 return start_index + 1
182 # if there is an explicit argument, try to match the
183 # optional's string arguments to only this
184 if explicit_arg is not None:
185 arg_count = match_argument(action, 'A')
187 # if the action is a single-dash option and takes no
188 # arguments, try to parse more single-dash options out
189 # of the tail of the option string
190 chars = self.prefix_chars
191 if arg_count == 0 and option_string[1] not in chars:
192 action_tuples.append((action, [], option_string))
193 char = option_string[0]
194 option_string = char + explicit_arg[0]
195 new_explicit_arg = explicit_arg[1:] or None
196 optionals_map = self._option_string_actions
197 if option_string in optionals_map:
198 action = optionals_map[option_string]
199 explicit_arg = new_explicit_arg
200 else:
201 msg = gettext('ignored explicit argument %r')
202 raise ArgumentError(action, msg % explicit_arg)
204 # if the action expect exactly one argument, we've
205 # successfully matched the option; exit the loop
206 elif arg_count == 1:
207 stop = start_index + 1
208 args = [explicit_arg]
209 action_tuples.append((action, args, option_string))
210 break
212 # error if a double-dash option did not use the
213 # explicit argument
214 else:
215 msg = gettext('ignored explicit argument %r')
216 raise ArgumentError(action, msg % explicit_arg)
218 # if there is no explicit argument, try to match the
219 # optional's string arguments with the following strings
220 # if successful, exit the loop
221 else:
222 start = start_index + 1
223 selected_patterns = arg_strings_pattern[start:]
224 self.active_actions = [action] # Added by argcomplete
225 _num_consumed_args[action] = 0 # Added by argcomplete
226 arg_count = match_argument(action, selected_patterns)
227 stop = start + arg_count
228 args = arg_strings[start:stop]
230 # Begin added by argcomplete
231 # If the pattern is not open (e.g. no + at the end), remove the action from active actions (since
232 # it wouldn't be able to consume any more args)
233 _num_consumed_args[action] = len(args)
234 if not action_is_open(action):
235 self.active_actions.remove(action)
236 # End added by argcomplete
238 action_tuples.append((action, args, option_string))
239 break
241 # add the Optional to the list and return the index at which
242 # the Optional's string args stopped
243 assert action_tuples
244 for action, args, option_string in action_tuples:
245 take_action(action, args, option_string)
246 return stop
248 # the list of Positionals left to be parsed; this is modified
249 # by consume_positionals()
250 positionals = self._get_positional_actions()
252 # function to convert arg_strings into positional actions
253 def consume_positionals(start_index):
254 # match as many Positionals as possible
255 match_partial = self._match_arguments_partial
256 selected_pattern = arg_strings_pattern[start_index:]
257 arg_counts = match_partial(positionals, selected_pattern)
259 # slice off the appropriate arg strings for each Positional
260 # and add the Positional and its args to the list
261 for action, arg_count in zip(positionals, arg_counts): # Added by argcomplete
262 self.active_actions.append(action) # Added by argcomplete
263 for action, arg_count in zip(positionals, arg_counts):
264 args = arg_strings[start_index : start_index + arg_count]
265 start_index += arg_count
266 _num_consumed_args[action] = len(args) # Added by argcomplete
267 take_action(action, args)
269 # slice off the Positionals that we just parsed and return the
270 # index at which the Positionals' string args stopped
271 positionals[:] = positionals[len(arg_counts) :]
272 return start_index
274 # consume Positionals and Optionals alternately, until we have
275 # passed the last option string
276 extras = []
277 start_index = 0
278 if option_string_indices:
279 max_option_string_index = max(option_string_indices)
280 else:
281 max_option_string_index = -1
282 while start_index <= max_option_string_index:
283 # consume any Positionals preceding the next option
284 next_option_string_index = min([index for index in option_string_indices if index >= start_index])
285 if start_index != next_option_string_index:
286 positionals_end_index = consume_positionals(start_index)
288 # only try to parse the next optional if we didn't consume
289 # the option string during the positionals parsing
290 if positionals_end_index > start_index:
291 start_index = positionals_end_index
292 continue
293 else:
294 start_index = positionals_end_index
296 # if we consumed all the positionals we could and we're not
297 # at the index of an option string, there were extra arguments
298 if start_index not in option_string_indices:
299 strings = arg_strings[start_index:next_option_string_index]
300 extras.extend(strings)
301 start_index = next_option_string_index
303 # consume the next optional and any arguments for it
304 start_index = consume_optional(start_index)
306 # consume any positionals following the last Optional
307 stop_index = consume_positionals(start_index)
309 # if we didn't consume all the argument strings, there were extras
310 extras.extend(arg_strings[stop_index:])
312 # if we didn't use all the Positional objects, there were too few
313 # arg strings supplied.
315 if positionals:
316 self.active_actions.append(positionals[0]) # Added by argcomplete
317 self.error(gettext('too few arguments'))
319 # make sure all required actions were present
320 for action in self._actions:
321 if action.required:
322 if action not in seen_actions:
323 name = _get_action_name(action)
324 self.error(gettext('argument %s is required') % name)
326 # make sure all required groups had one option present
327 for group in self._mutually_exclusive_groups:
328 if group.required:
329 for action in group._group_actions:
330 if action in seen_non_default_actions:
331 break
333 # if no actions were used, report the error
334 else:
335 names = [
336 str(_get_action_name(action)) for action in group._group_actions if action.help is not SUPPRESS
337 ]
338 msg = gettext('one of the arguments %s is required')
339 self.error(msg % ' '.join(names))
341 # return the updated namespace and the extra arguments
342 return namespace, extras