Coverage for .tox/cov/lib/python3.11/site-packages/confattr/utils.py: 100%

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1#!./runmodule.sh 

2 

3''' 

4This module contains classes and functions that :mod:`confattr` uses internally but which might be useful for other python projects, too. 

5''' 

6 

7import re 

8import argparse 

9import inspect 

10import textwrap 

11import shlex 

12import functools 

13import enum 

14import typing 

15from collections.abc import Sequence, Callable 

16 

17if typing.TYPE_CHECKING: 

18 from typing_extensions import Unpack, Self 

19 

20 

21# ---------- shlex quote ---------- 

22 

23def readable_quote(value: str) -> str: 

24 ''' 

25 This function has the same goal like :func:`shlex.quote` but tries to generate better readable output. 

26 

27 :param value: A value which is intended to be used as a command line argument 

28 :return: A POSIX compliant quoted version of :paramref:`~confattr.utils.readable_quote.value` 

29 ''' 

30 out = shlex.quote(value) 

31 if out == value: 

32 return out 

33 

34 if '"\'"' in out and '"' not in value: 

35 return '"' + value + '"' 

36 

37 return out 

38 

39 

40# ---------- sorted enum ---------- 

41 

42@functools.total_ordering 

43class SortedEnum(enum.Enum): 

44 

45 ''' 

46 By default it is assumed that the values are defined in ascending order ``ONE='one'; TWO='two'; THREE='three'``. 

47 If you want to define them in descending order ``THREE='three'; TWO='two'; ONE='one'`` you can pass ``descending = True`` to the subclass. 

48 This requires Python 3.10.0a4 or newer. 

49 On older versions it causes a ``TypeError: __prepare__() got an unexpected keyword argument 'descending'``. 

50 This was fixed in `commit 6ec0adefad <https://github.com/python/cpython/commit/6ec0adefad60ec7cdec61c44baecf1dccc1461ab>`__. 

51 ''' 

52 

53 descending: bool 

54 

55 @classmethod 

56 def __init_subclass__(cls, descending: bool = False): 

57 cls.descending = descending 

58 

59 def __lt__(self, other: typing.Any) -> bool: 

60 if self.__class__ is other.__class__: 

61 l: 'tuple[SortedEnum, ...]' = tuple(type(self)) 

62 if self.descending: 

63 left = other 

64 right = self 

65 else: 

66 left = self 

67 right = other 

68 return l.index(left) < l.index(right) 

69 return NotImplemented 

70 

71 def __add__(self, other: object) -> 'Self': 

72 if isinstance(other, int): 

73 l: 'tuple[Self, ...]' = tuple(type(self)) 

74 i = l.index(self) 

75 if self.descending: 

76 other = -other 

77 i += other 

78 if i < 0: 

79 i = 0 

80 elif i >= len(l): 

81 i = len(l) - 1 

82 return l[i] 

83 return NotImplemented 

84 

85 def __sub__(self, other: object) -> 'Self': 

86 if isinstance(other, int): 

87 return self + (-other) 

88 return NotImplemented 

89 

90 

91 

92# ---------- argparse help formatter ---------- 

93 

94class HelpFormatter(argparse.RawDescriptionHelpFormatter): 

95 

96 ''' 

97 A subclass of :class:`argparse.HelpFormatter` which keeps paragraphs 

98 separated by an empty line as separate paragraphs and 

99 and which does *not* merge different list items to a single line. 

100 

101 Lines are wrapped to not exceed a length of :attr:`~confattr.utils.HelpFormatter.max_width` characters, 

102 although not strictly to prevent URLs from breaking. 

103 

104 If a line ends with a double backslash this line will not be merged with the following line 

105 and the double backslash (and spaces directly before it) will be removed. 

106 

107 As the doc string of :class:`argparse.HelpFormatter` states 

108 

109 Only the name of this class is considered a public API. 

110 All the methods provided by the class are considered an implementation detail. 

111 

112 Therefore I may be forced to change the methods' signatures if :class:`argparse.HelpFormatter` is changed. 

113 But I hope that I can keep the class attributes backward compatible so that you can create your own formatter class 

114 by subclassing this class and changing the values of the class variables. 

115 

116 If you want to use this class without an :class:`argparse.ArgumentParser` pass it to the constructor of :class:`~confattr.utils.HelpFormatterWrapper` and use that instead. 

117 ''' 

118 

119 #: Wrap lines so that they are no longer than this number of characters. 

120 max_width = 70 

121 

122 #: This value is assigned to :attr:`textwrap.TextWrapper.break_long_words`. This defaults to False to prevent URLs from breaking. 

123 break_long_words = False 

124 

125 #: This value is assigned to :attr:`textwrap.TextWrapper.break_on_hyphens`. This defaults to False to prevent URLs from breaking. 

126 break_on_hyphens = False 

127 

128 #: If a match is found this line is not merged with the following and the match is removed. This may *not* contain any capturing groups. 

129 regex_linebreak = re.escape(r'\\') + '(?:\n|$)' 

130 

131 #: If a match is found this line is not merged with the preceeding line. This regular expression must contain exactly one capturing group. This group defines the indentation. Everything that is matched but not part of that group is removed. 

132 regex_list_item = '(?:^|\n)' + r'(\s*(?:[-+*!/.]|[0-9]+[.)])(?: \[[ x~]\])? )' 

133 

134 def __init__(self, 

135 prog: str, 

136 indent_increment: int = 2, 

137 max_help_position: int = 24, 

138 width: 'int|None' = None, 

139 ) -> None: 

140 ''' 

141 :param prog: The name of the program 

142 :param width: Wrap lines so that they are no longer than this number of characters. If this value is None or bigger than :attr:`~confattr.utils.HelpFormatter.max_width` then :attr:`~confattr.utils.HelpFormatter.max_width` is used instead. 

143 ''' 

144 if width is None or width >= self.max_width: 

145 width = self.max_width 

146 super().__init__(prog, indent_increment, max_help_position, width) 

147 

148 

149 # ------- override methods of parent class ------- 

150 

151 def _fill_text(self, text: str, width: int, indent: str) -> str: 

152 ''' 

153 This method joins the lines returned by :meth:`~confattr.utils.HelpFormatter._split_lines`. 

154 

155 This method is used to format text blocks such as the description. 

156 It is *not* used to format the help of arguments—see :meth:`~confattr.utils.HelpFormatter._split_lines` for that. 

157 ''' 

158 return '\n'.join(self._split_lines(text, width, indent=indent)) 

159 

160 def _split_lines(self, text: str, width: int, *, indent: str = '') -> 'list[str]': 

161 ''' 

162 This method cleans :paramref:`~confattr.utils.HelpFormatter._split_lines.text` with :func:`inspect.cleandoc` and 

163 wraps the lines with :meth:`textwrap.TextWrapper.wrap`. 

164 Paragraphs separated by an empty line are kept as separate paragraphs. 

165 

166 This method is used to format the help of arguments and 

167 indirectly through :meth:`~confattr.utils.HelpFormatter._fill_text` to format text blocks such as description. 

168 

169 :param text: The text to be formatted 

170 :param width: The maximum width of the resulting lines (Depending on the values of :attr:`~confattr.utils.HelpFormatter.break_long_words` and :attr:`~confattr.utils.HelpFormatter.break_on_hyphens` this width can be exceeded in order to not break URLs.) 

171 :param indent: A str to be prepended to all lines. The original :class:`argparse.HelpFormatter` does not have this parameter, I have added it so that I can use this method in :meth:`~confattr.utils.HelpFormatter._fill_text`. 

172 ''' 

173 lines = [] 

174 # The original implementation does not use cleandoc 

175 # it simply gets rid of all indentation and line breaks with 

176 # self._whitespace_matcher.sub(' ', text).strip() 

177 # https://github.com/python/cpython/blob/main/Lib/argparse.py 

178 text = inspect.cleandoc(text) 

179 wrapper = textwrap.TextWrapper(width=width, 

180 break_long_words=self.break_long_words, break_on_hyphens=self.break_on_hyphens) 

181 for par in re.split('\n\\s*\n', text): 

182 for ln in re.split(self.regex_linebreak, par): 

183 wrapper.initial_indent = indent 

184 wrapper.subsequent_indent = indent 

185 pre_bullet_items = re.split(self.regex_list_item, ln) 

186 lines.extend(wrapper.wrap(pre_bullet_items[0])) 

187 for i in range(1, len(pre_bullet_items), 2): 

188 bullet = pre_bullet_items[i] 

189 item = pre_bullet_items[i+1] 

190 add_indent = ' ' * len(bullet) 

191 wrapper.initial_indent = indent + bullet 

192 wrapper.subsequent_indent = indent + add_indent 

193 item = item.replace('\n'+add_indent, '\n') 

194 lines.extend(wrapper.wrap(item)) 

195 lines.append('') 

196 

197 lines = lines[:-1] 

198 

199 return lines 

200 

201 

202if typing.TYPE_CHECKING: 

203 class HelpFormatterKwargs(typing.TypedDict, total=False): 

204 prog: str 

205 indent_increment: int 

206 max_help_position: int 

207 width: int 

208 

209 

210class HelpFormatterWrapper: 

211 

212 ''' 

213 The doc string of :class:`argparse.HelpFormatter` states: 

214 

215 Only the name of this class is considered a public API. 

216 All the methods provided by the class are considered an implementation detail. 

217 

218 This is a wrapper which tries to stay backward compatible even if :class:`argparse.HelpFormatter` changes. 

219 ''' 

220 

221 def __init__(self, formatter_class: 'type[argparse.HelpFormatter]', **kw: 'Unpack[HelpFormatterKwargs]') -> None: 

222 ''' 

223 :param formatter_class: :class:`argparse.HelpFormatter` or any of it's subclasses (:class:`argparse.RawDescriptionHelpFormatter`, :class:`argparse.RawTextHelpFormatter`, :class:`argparse.ArgumentDefaultsHelpFormatter`, :class:`argparse.MetavarTypeHelpFormatter` or :class:`~confattr.utils.HelpFormatter`) 

224 :param prog: The name of the program 

225 :param indent_increment: The number of spaces by which to indent the contents of a section 

226 :param max_help_position: The maximal indentation of the help of arguments. If argument names + meta vars + separators are longer than this the help starts on the next line. 

227 :param width: Maximal number of characters per line 

228 ''' 

229 kw.setdefault('prog', '') 

230 self.formatter = formatter_class(**kw) 

231 

232 

233 # ------- format directly ------- 

234 

235 def format_text(self, text: str) -> str: 

236 ''' 

237 Format a text and return it immediately without adding it to :meth:`~confattr.utils.HelpFormatterWrapper.format_help`. 

238 ''' 

239 return self.formatter._format_text(text) 

240 

241 def format_item(self, bullet: str, text: str) -> str: 

242 ''' 

243 Format a list item and return it immediately without adding it to :meth:`~confattr.utils.HelpFormatterWrapper.format_help`. 

244 ''' 

245 # apply section indentation 

246 bullet = ' ' * self.formatter._current_indent + bullet 

247 width = max(self.formatter._width - self.formatter._current_indent, 11) 

248 

249 # _fill_text does not distinguish between textwrap's initial_indent and subsequent_indent 

250 # instead I am using bullet for both and then replace the bullet with whitespace on all but the first line 

251 text = self.formatter._fill_text(text, width, bullet) 

252 pattern_bullet = '(?<=\n)' + re.escape(bullet) 

253 indent = ' ' * len(bullet) 

254 text = re.sub(pattern_bullet, indent, text) 

255 return text + '\n' 

256 

257 

258 # ------- input ------- 

259 

260 def add_start_section(self, heading: str) -> None: 

261 ''' 

262 Start a new section. 

263 

264 This influences the formatting of following calls to :meth:`~confattr.utils.HelpFormatterWrapper.add_text` and :meth:`~confattr.utils.HelpFormatterWrapper.add_item`. 

265 

266 You can call this method again before calling :meth:`~confattr.utils.HelpFormatterWrapper.add_end_section` to create a subsection. 

267 ''' 

268 self.formatter.start_section(heading) 

269 

270 def add_end_section(self) -> None: 

271 ''' 

272 End the last section which has been started with :meth:`~confattr.utils.HelpFormatterWrapper.add_start_section`. 

273 ''' 

274 self.formatter.end_section() 

275 

276 def add_text(self, text: str) -> None: 

277 ''' 

278 Add some text which will be formatted when calling :meth:`~confattr.utils.HelpFormatterWrapper.format_help`. 

279 ''' 

280 self.formatter.add_text(text) 

281 

282 def add_start_list(self) -> None: 

283 ''' 

284 Start a new list which can be filled with :meth:`~confattr.utils.HelpFormatterWrapper.add_item`. 

285 ''' 

286 # nothing to do, this exists only as counter piece for add_end_list 

287 

288 def add_item(self, text: str, bullet: str = '- ') -> None: 

289 ''' 

290 Add a list item which will be formatted when calling :meth:`~confattr.utils.HelpFormatterWrapper.format_help`. 

291 A list must be started with :meth:`~confattr.utils.HelpFormatterWrapper.add_start_list` and ended with :meth:`~confattr.utils.HelpFormatterWrapper.add_end_list`. 

292 ''' 

293 self.formatter._add_item(self.format_item, (bullet, text)) 

294 

295 def add_end_list(self) -> None: 

296 ''' 

297 End a list. This must be called after the last :meth:`~confattr.utils.HelpFormatterWrapper.add_item`. 

298 ''' 

299 def identity(x: str) -> str: 

300 return x 

301 self.formatter._add_item(identity, ('\n',)) 

302 

303 # ------- output ------- 

304 

305 def format_help(self) -> str: 

306 ''' 

307 Format everything that has been added with :meth:`~confattr.utils.HelpFormatterWrapper.add_start_section`, :meth:`~confattr.utils.HelpFormatterWrapper.add_text` and :meth:`~confattr.utils.HelpFormatterWrapper.add_item`. 

308 ''' 

309 return self.formatter.format_help() 

310 

311 

312# ---------- argparse actions ---------- 

313 

314class CallAction(argparse.Action): 

315 

316 def __init__(self, option_strings: 'Sequence[str]', dest: str, callback: 'Callable[[], None]', help: 'str|None' = None, nargs: 'int|str' = 0) -> None: 

317 if help is None: 

318 if callback.__doc__ is None: 

319 raise TypeError("missing doc string for function %s" % callback.__name__) 

320 help = callback.__doc__.strip() 

321 argparse.Action.__init__(self, option_strings, dest, nargs=nargs, help=help) 

322 self.callback = callback 

323 

324 def __call__(self, parser: argparse.ArgumentParser, namespace: argparse.Namespace, values: object, option_string: 'str|None' = None) -> None: 

325 self.callback(*values)