# coding=utf-8 """ AutoCompleter interprets the argparse.ArgumentParser internals to automatically generate the completion options for each argument. How to supply completion options for each argument: argparse Choices - pass a list of values to the choices parameter of an argparse argument. ex: parser.add_argument('-o', '--options', dest='options', choices=['An Option', 'SomeOtherOption']) arg_choices dictionary lookup arg_choices is a dict() mapping from argument name to one of 3 possible values: ex: parser = argparse.ArgumentParser() parser.add_argument('-o', '--options', dest='options') choices = {} mycompleter = AutoCompleter(parser, completer, 1, choices) - static list - provide a static list for each argument name ex: choices['options'] = ['An Option', 'SomeOtherOption'] - choices function - provide a function that returns a list for each argument name ex: def generate_choices(): return ['An Option', 'SomeOtherOption'] choices['options'] = generate_choices - custom completer function - provide a completer function that will return the list of completion arguments ex 1: def my_completer(text: str, line: str, begidx: int, endidx:int): my_choices = [...] return my_choices choices['options'] = (my_completer) ex 2: def my_completer(text: str, line: str, begidx: int, endidx:int, extra_param: str, another: int): my_choices = [...] return my_choices completer_params = {'extra_param': 'my extra', 'another': 5} choices['options'] = (my_completer, completer_params) How to supply completion choice lists or functions for sub-commands: subcmd_args_lookup is used to supply a unique pair of arg_choices and subcmd_args_lookup for each sub-command in an argparser subparser group. This requires your subparser group to be named with the dest parameter ex: parser = ArgumentParser() subparsers = parser.add_subparsers(title='Actions', dest='action') subcmd_args_lookup maps a named subparser group to a subcommand group dictionary The subcommand group dictionary maps subcommand names to tuple(arg_choices, subcmd_args_lookup) For more details of this more complex approach see tab_autocompletion.py in the examples Copyright 2018 Eric Lin Released under MIT license, see LICENSE file """ import argparse from colorama import Fore import sys from typing import List, Dict, Tuple, Callable, Union # imports copied from argparse to support our customized argparse functions from argparse import ZERO_OR_MORE, ONE_OR_MORE, ArgumentError, _ import re as _re from .rl_utils import rl_force_redisplay class _RangeAction(object): def __init__(self, nargs: Union[int, str, Tuple[int, int], None]): self.nargs_min = None self.nargs_max = None # pre-process special ranged nargs if isinstance(nargs, tuple): if len(nargs) != 2 or not isinstance(nargs[0], int) or not isinstance(nargs[1], int): raise ValueError('Ranged values for nargs must be a tuple of 2 integers') if nargs[0] >= nargs[1]: raise ValueError('Invalid nargs range. The first value must be less than the second') if nargs[0] < 0: raise ValueError('Negative numbers are invalid for nargs range.') narg_range = nargs self.nargs_min = nargs[0] self.nargs_max = nargs[1] if narg_range[0] == 0: if narg_range[1] > 1: self.nargs_adjusted = '*' else: # this shouldn't use a range tuple, but yet here we are self.nargs_adjusted = '?' else: self.nargs_adjusted = '+' else: self.nargs_adjusted = nargs class _StoreRangeAction(argparse._StoreAction, _RangeAction): def __init__(self, option_strings, dest, nargs=None, const=None, default=None, type=None, choices=None, required=False, help=None, metavar=None): _RangeAction.__init__(self, nargs) argparse._StoreAction.__init__(self, option_strings=option_strings, dest=dest, nargs=self.nargs_adjusted, const=const, default=default, type=type, choices=choices, required=required, help=help, metavar=metavar) class _AppendRangeAction(argparse._AppendAction, _RangeAction): def __init__(self, option_strings, dest, nargs=None, const=None, default=None, type=None, choices=None, required=False, help=None, metavar=None): _RangeAction.__init__(self, nargs) argparse._AppendAction.__init__(self, option_strings=option_strings, dest=dest, nargs=self.nargs_adjusted, const=const, default=default, type=type, choices=choices, required=required, help=help, metavar=metavar) def register_custom_actions(parser: argparse.ArgumentParser): """Register custom argument action types""" parser.register('action', None, _StoreRangeAction) parser.register('action', 'store', _StoreRangeAction) parser.register('action', 'append', _AppendRangeAction) class AutoCompleter(object): """Automatically command line tab completion based on argparse parameters""" class _ArgumentState(object): def __init__(self): self.min = None self.max = None self.count = 0 self.needed = False self.variable = False def reset(self): """reset tracking values""" self.min = None self.max = None self.count = 0 self.needed = False self.variable = False def __init__(self, parser: argparse.ArgumentParser, token_start_index: int = 1, arg_choices: Dict[str, Union[List, Tuple, Callable]] = None, subcmd_args_lookup: dict = None, tab_for_arg_help: bool = True): """ Create an AutoCompleter :param parser: ArgumentParser instance :param token_start_index: index of the token to start parsing at :param arg_choices: dictionary mapping from argparse argument 'dest' name to list of choices :param subcmd_args_lookup: mapping a sub-command group name to a tuple to fill the child\ AutoCompleter's arg_choices and subcmd_args_lookup parameters """ if not subcmd_args_lookup: subcmd_args_lookup = {} forward_arg_choices = True else: forward_arg_choices = False self._parser = parser self._arg_choices = arg_choices.copy() if arg_choices is not None else {} self._token_start_index = token_start_index self._tab_for_arg_help = tab_for_arg_help self._flags = [] # all flags in this command self._flags_without_args = [] # all flags that don't take arguments self._flag_to_action = {} # maps flags to the argparse action object self._positional_actions = [] # argument names for positional arguments (by position index) # maps action name to sub-command autocompleter: # action_name -> dict(sub_command -> completer) self._positional_completers = {} # Start digging through the argparse structures. # _actions is the top level container of parameter definitions for action in self._parser._actions: # if there are choices defined, record them in the arguments dictionary if action.choices is not None: self._arg_choices[action.dest] = action.choices # if the parameter is flag based, it will have option_strings if action.option_strings: # record each option flag for option in action.option_strings: self._flags.append(option) self._flag_to_action[option] = action if action.nargs == 0: self._flags_without_args.append(option) else: self._positional_actions.append(action) if isinstance(action, argparse._SubParsersAction): sub_completers = {} sub_commands = [] args_for_action = subcmd_args_lookup[action.dest]\ if action.dest in subcmd_args_lookup else {} for subcmd in action.choices: (subcmd_args, subcmd_lookup) = args_for_action[subcmd] if \ subcmd in args_for_action else \ (arg_choices, subcmd_args_lookup) if forward_arg_choices else ({}, {}) subcmd_start = token_start_index + len(self._positional_actions) sub_completers[subcmd] = AutoCompleter(action.choices[subcmd], subcmd_start, arg_choices=subcmd_args, subcmd_args_lookup=subcmd_lookup) sub_commands.append(subcmd) self._positional_completers[action.dest] = sub_completers self._arg_choices[action.dest] = sub_commands def complete_command(self, tokens: List[str], text: str, line: str, begidx: int, endidx: int) -> List[str]: """Complete the command using the argparse metadata and provided argument dictionary""" # Count which positional argument index we're at now. Loop through all tokens on the command line so far # Skip any flags or flag parameter tokens next_pos_arg_index = 0 pos_arg = AutoCompleter._ArgumentState() pos_action = None flag_arg = AutoCompleter._ArgumentState() flag_action = None matched_flags = [] current_is_positional = False consumed_arg_values = {} # dict(arg_name -> [values, ...]) # the following are nested functions that have full access to all variables in the parent # function including variables declared and updated after this function. Variable values # are current at the point the nested functions are invoked (as in, they do not receive a # snapshot of these values, they directly access the current state of variables in the # parent function) def consume_flag_argument() -> None: """Consuming token as a flag argument""" # we're consuming flag arguments # if this is not empty and is not another potential flag, count towards flag arguments if token and token[0] not in self._parser.prefix_chars and flag_action is not None: flag_arg.count += 1 # does this complete a option item for the flag arg_choices = self._resolve_choices_for_arg(flag_action) # if the current token matches the current position's autocomplete argument list, # track that we've used it already. Unless this is the current token, then keep it. if not is_last_token and token in arg_choices: consumed_arg_values.setdefault(flag_action.dest, []) consumed_arg_values[flag_action.dest].append(token) def consume_positional_argument() -> None: """Consuming token as positional argument""" pos_arg.count += 1 # does this complete a option item for the flag arg_choices = self._resolve_choices_for_arg(pos_action) # if the current token matches the current position's autocomplete argument list, # track that we've used it already. Unless this is the current token, then keep it. if not is_last_token and token in arg_choices: consumed_arg_values.setdefault(pos_action.dest, []) consumed_arg_values[pos_action.dest].append(token) is_last_token = False for idx, token in enumerate(tokens): is_last_token = idx >= len(tokens) - 1 # Only start at the start token index if idx >= self._token_start_index: current_is_positional = False # Are we consuming flag arguments? if not flag_arg.needed: # we're not consuming flag arguments, is the current argument a potential flag? if len(token) > 0 and token[0] in self._parser.prefix_chars and\ (is_last_token or (not is_last_token and token != '-')): # reset some tracking values flag_arg.reset() # don't reset positional tracking because flags can be interspersed anywhere between positionals flag_action = None # does the token fully match a known flag? if token in self._flag_to_action: flag_action = self._flag_to_action[token] elif hasattr(self._parser, 'allow_abbrev') and self._parser.allow_abbrev: candidates_flags = [flag for flag in self._flag_to_action if flag.startswith(token)] if len(candidates_flags) == 1: flag_action = self._flag_to_action[candidates_flags[0]] if flag_action is not None: # resolve argument counts self._process_action_nargs(flag_action, flag_arg) if not is_last_token and not isinstance(flag_action, argparse._AppendAction): matched_flags.extend(flag_action.option_strings) # current token isn't a potential flag # - does the last flag accept variable arguments? # - have we reached the max arg count for the flag? elif not flag_arg.variable or flag_arg.count >= flag_arg.max: # previous flag doesn't accept variable arguments, count this as a positional argument # reset flag tracking variables flag_arg.reset() flag_action = None current_is_positional = True if len(token) > 0 and pos_action is not None and pos_arg.count < pos_arg.max: # we have positional action match and we haven't reached the max arg count, consume # the positional argument and move on. consume_positional_argument() elif pos_action is None or pos_arg.count >= pos_arg.max: # if we don't have a current positional action or we've reached the max count for the action # close out the current positional argument state and set up for the next one pos_index = next_pos_arg_index next_pos_arg_index += 1 pos_arg.reset() pos_action = None # are we at a sub-command? If so, forward to the matching completer if pos_index < len(self._positional_actions): action = self._positional_actions[pos_index] pos_name = action.dest if pos_name in self._positional_completers: sub_completers = self._positional_completers[pos_name] if token in sub_completers: return sub_completers[token].complete_command(tokens, text, line, begidx, endidx) pos_action = action self._process_action_nargs(pos_action, pos_arg) consume_positional_argument() elif not is_last_token and pos_arg.max is not None: pos_action = None pos_arg.reset() else: consume_flag_argument() else: consume_flag_argument() # don't reset this if we're on the last token - this allows completion to occur on the current token if not is_last_token and flag_arg.min is not None: flag_arg.needed = flag_arg.count < flag_arg.min # if we don't have a flag to populate with arguments and the last token starts with # a flag prefix then we'll complete the list of flag options completion_results = [] if not flag_arg.needed and len(tokens[-1]) > 0 and tokens[-1][0] in self._parser.prefix_chars: return AutoCompleter.basic_complete(text, line, begidx, endidx, [flag for flag in self._flags if flag not in matched_flags]) # we're not at a positional argument, see if we're in a flag argument elif not current_is_positional: # current_items = [] if flag_action is not None: consumed = consumed_arg_values[flag_action.dest]\ if flag_action.dest in consumed_arg_values else [] # current_items.extend(self._resolve_choices_for_arg(flag_action, consumed)) completion_results = self._complete_for_arg(flag_action, text, line, begidx, endidx, consumed) if not completion_results: self._print_action_help(flag_action) # ok, we're not a flag, see if there's a positional argument to complete else: if pos_action is not None: pos_name = pos_action.dest consumed = consumed_arg_values[pos_name] if pos_name in consumed_arg_values else [] completion_results = self._complete_for_arg(pos_action, text, line, begidx, endidx, consumed) if not completion_results: self._print_action_help(pos_action) return completion_results @staticmethod def _process_action_nargs(action: argparse.Action, arg_state: _ArgumentState) -> None: if isinstance(action, _RangeAction): arg_state.min = action.nargs_min arg_state.max = action.nargs_max arg_state.variable = True if arg_state.min is None or arg_state.max is None: if action.nargs is None: arg_state.min = 1 arg_state.max = 1 elif action.nargs == '+': arg_state.min = 1 arg_state.max = float('inf') arg_state.variable = True elif action.nargs == '*': arg_state.min = 0 arg_state.max = float('inf') arg_state.variable = True elif action.nargs == '?': arg_state.min = 0 arg_state.max = 1 arg_state.variable = True else: arg_state.min = action.nargs arg_state.max = action.nargs def _complete_for_arg(self, action: argparse.Action, text: str, line: str, begidx: int, endidx: int, used_values=()) -> List[str]: if action.dest in self._arg_choices: arg_choices = self._arg_choices[action.dest] if isinstance(arg_choices, tuple) and len(arg_choices) > 0 and callable(arg_choices[0]): completer = arg_choices[0] list_args = None kw_args = None for index in range(1, len(arg_choices)): if isinstance(arg_choices[index], list) or isinstance(arg_choices[index], tuple): list_args = arg_choices[index] elif isinstance(arg_choices[index], dict): kw_args = arg_choices[index] if list_args is not None and kw_args is not None: return completer(text, line, begidx, endidx, *list_args, **kw_args) elif list_args is not None: return completer(text, line, begidx, endidx, *list_args) elif kw_args is not None: return completer(text, line, begidx, endidx, **kw_args) else: return completer(text, line, begidx, endidx) else: return AutoCompleter.basic_complete(text, line, begidx, endidx, self._resolve_choices_for_arg(action, used_values)) return [] def _resolve_choices_for_arg(self, action: argparse.Action, used_values=()) -> List[str]: if action.dest in self._arg_choices: args = self._arg_choices[action.dest] if callable(args): args = args() try: iter(args) except TypeError: pass else: # filter out arguments we already used args = [arg for arg in args if arg not in used_values] if len(args) > 0: return args return [] def _print_action_help(self, action: argparse.Action) -> None: if not self._tab_for_arg_help: return if action.option_strings: flags = ', '.join(action.option_strings) param = '' if action.nargs is None or action.nargs != 0: param += ' ' + str(action.dest).upper() prefix = '{}{}'.format(flags, param) else: prefix = '{}'.format(str(action.dest).upper()) prefix = ' {0: <{width}} '.format(prefix, width=20) pref_len = len(prefix) help_lines = action.help.splitlines() if len(help_lines) == 1: print('\nHint:\n{}{}\n'.format(prefix, help_lines[0])) else: out_str = '\n{}'.format(prefix) out_str += '\n{0: <{width}}'.format('', width=pref_len).join(help_lines) print('\nHint:' + out_str + '\n') # Redraw prompt and input line rl_force_redisplay() # noinspection PyUnusedLocal @staticmethod def basic_complete(text: str, line: str, begidx: int, endidx: int, match_against: List[str]) -> List[str]: """ Performs tab completion against a list :param text: str - the string prefix we are attempting to match (all returned matches must begin with it) :param line: str - the current input line with leading whitespace removed :param begidx: int - the beginning index of the prefix text :param endidx: int - the ending index of the prefix text :param match_against: Collection - the list being matched against :return: List[str] - a list of possible tab completions """ return [cur_match for cur_match in match_against if cur_match.startswith(text)] ############################################################################### # Unless otherwise noted, everything below this point are copied from Python's # argparse implementation with minor tweaks to adjust output. # Changes are noted if it's buried in a block of copied code. Otherwise the # function will check for a special case and fall back to the parent function ############################################################################### class ACHelpFormatter(argparse.HelpFormatter): """Custom help formatter to configure ordering of help text""" 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 %= 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 = [] # Begin cmd2 customization (separates required and optional, applies to all changes in this function) required_options = [] for action in actions: if action.option_strings: if action.required: required_options.append(action) else: optionals.append(action) else: positionals.append(action) # End cmd2 customization # build full usage string format = self._format_actions_usage action_usage = format(positionals + required_options + optionals, 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: # Begin cmd2 customization # break usage into wrappable parts part_regexp = r'\(.*?\)+|\[.*?\]+|\S+' opt_usage = format(optionals, groups) pos_usage = format(positionals, groups) req_usage = format(required_options, groups) opt_parts = _re.findall(part_regexp, opt_usage) pos_parts = _re.findall(part_regexp, pos_usage) req_parts = _re.findall(part_regexp, req_usage) assert ' '.join(opt_parts) == opt_usage assert ' '.join(pos_parts) == pos_usage assert ' '.join(req_parts) == req_usage # End cmd2 customization # 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) # Begin cmd2 customization if opt_parts: lines = get_lines([prog] + pos_parts, indent, prefix) lines.extend(get_lines(req_parts, indent)) lines.extend(get_lines(opt_parts, indent)) elif pos_parts: lines = get_lines([prog] + pos_parts, indent, prefix) lines.extend(get_lines(req_parts, indent)) else: lines = [prog] # End cmd2 customization # if prog is long, put it on its own line else: indent = ' ' * len(prefix) # Begin cmd2 customization parts = pos_parts + req_parts + opt_parts lines = get_lines(parts, indent) if len(lines) > 1: lines = [] lines.extend(get_lines(pos_parts, indent)) lines.extend(get_lines(req_parts, indent)) lines.extend(get_lines(opt_parts, indent)) # End cmd2 customization lines = [prog] + lines # join lines into usage usage = '\n'.join(lines) # prefix with 'usage:' return '%s%s\n\n' % (prefix, usage) 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) return ', '.join(parts) # Begin cmd2 customization (less verbose) # if the Optional takes a value, format is: # -s, --long ARGS else: default = self._get_default_metavar_for_optional(action) args_string = self._format_args(action, default) return ', '.join(action.option_strings) + ' ' + args_string # End cmd2 customization 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] # Begin cmd2 customization (added space after comma) result = '{%s}' % ', '.join(choice_strs) # End cmd2 customization 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) # Begin cmd2 customization (less verbose) if isinstance(action, _RangeAction) and \ action.nargs_min is not None and action.nargs_max is not None: result = '{}{{{}..{}}}'.format('%s' % get_metavar(1), action.nargs_min, action.nargs_max) elif action.nargs == ZERO_OR_MORE: result = '[%s [...]]' % get_metavar(1) elif action.nargs == ONE_OR_MORE: result = '%s [...]' % get_metavar(1) # End cmd2 customization else: result = super()._format_args(action, default_metavar) return result def _split_lines(self, text, width): return text.splitlines() class ACArgumentParser(argparse.ArgumentParser): """Custom argparse class to override error method to change default help text.""" def __init__(self, *args, **kwargs): if 'formatter_class' not in kwargs: kwargs['formatter_class'] = ACHelpFormatter super().__init__(*args, **kwargs) register_custom_actions(self) self._custom_error_message = '' # Begin cmd2 customization def set_custom_message(self, custom_message=''): """ Allows an error message override to the error() function, useful when forcing a re-parse of arguments with newly required parameters """ self._custom_error_message = custom_message # End cmd2 customization def error(self, message): """Custom error override. Allows application to control the error being displayed by argparse""" if len(self._custom_error_message) > 0: message = self._custom_error_message self._custom_error_message = '' lines = message.split('\n') linum = 0 formatted_message = '' for line in lines: if linum == 0: formatted_message = 'Error: ' + line else: formatted_message += '\n ' + line linum += 1 sys.stderr.write(Fore.LIGHTRED_EX + '{}\n\n'.format(formatted_message) + Fore.RESET) # sys.stderr.write('{}\n\n'.format(formatted_message)) self.print_help() sys.exit(1) def format_help(self): """Copy of format_help() from argparse.ArgumentParser with tweaks to separately display required parameters""" formatter = self._get_formatter() # usage formatter.add_usage(self.usage, self._actions, self._mutually_exclusive_groups) # description formatter.add_text(self.description) # Begin cmd2 customization (separate required and optional arguments) # positionals, optionals and user-defined groups for action_group in self._action_groups: if action_group.title == 'optional arguments': # check if the arguments are required, group accordingly req_args = [] opt_args = [] for action in action_group._group_actions: if action.required: req_args.append(action) else: opt_args.append(action) # separately display required arguments formatter.start_section('required arguments') formatter.add_text(action_group.description) formatter.add_arguments(req_args) formatter.end_section() # now display truly optional arguments formatter.start_section(action_group.title) formatter.add_text(action_group.description) formatter.add_arguments(opt_args) formatter.end_section() else: formatter.start_section(action_group.title) formatter.add_text(action_group.description) formatter.add_arguments(action_group._group_actions) formatter.end_section() # End cmd2 customization # epilog formatter.add_text(self.epilog) # determine help from format above return formatter.format_help() def _get_nargs_pattern(self, action): # Override _get_nargs_pattern behavior to use the nargs ranges provided by AutoCompleter if isinstance(action, _RangeAction) and \ action.nargs_min is not None and action.nargs_max is not None: nargs_pattern = '(-*A{{{},{}}}-*)'.format(action.nargs_min, action.nargs_max) # if this is an optional action, -- is not allowed if action.option_strings: nargs_pattern = nargs_pattern.replace('-*', '') nargs_pattern = nargs_pattern.replace('-', '') return nargs_pattern return super(ACArgumentParser, self)._get_nargs_pattern(action) 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: if isinstance(action, _RangeAction) and \ action.nargs_min is not None and action.nargs_max is not None: raise ArgumentError(action, 'Expected between {} and {} arguments'.format(action.nargs_min, action.nargs_max)) return super(ACArgumentParser, self)._match_argument(action, arg_strings_pattern)