Coverage for .tox/cov/lib/python3.12/site-packages/confattr/utils.py: 100%
123 statements
« prev ^ index » next coverage.py v7.5.3, created at 2024-05-29 08:17 +0200
« prev ^ index » next coverage.py v7.5.3, created at 2024-05-29 08:17 +0200
1#!./runmodule.sh
3'''
4This module contains classes and functions that :mod:`confattr` uses internally but which might be useful for other python projects, too.
5'''
7import re
8import argparse
9import inspect
10import textwrap
11import shlex
12import functools
13import enum
14import typing
15from collections.abc import Sequence, Callable
17if typing.TYPE_CHECKING:
18 from typing_extensions import Unpack, Self
21# ---------- shlex quote ----------
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.
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
34 if '"\'"' in out and '"' not in value:
35 return '"' + value + '"'
37 return out
40# ---------- sorted enum ----------
42@functools.total_ordering
43class SortedEnum(enum.Enum):
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 '''
53 descending: bool
55 @classmethod
56 def __init_subclass__(cls, descending: bool = False):
57 cls.descending = descending
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
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
85 def __sub__(self, other: object) -> 'Self':
86 if isinstance(other, int):
87 return self + (-other)
88 return NotImplemented
92# ---------- argparse help formatter ----------
94class HelpFormatter(argparse.RawDescriptionHelpFormatter):
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.
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.
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.
107 `Non breaking spaces <https://en.wikipedia.org/wiki/Nbsp>`_ can be used to prevent line breaks.
108 They will be replaced with normal spaces after line breaking.
110 As the doc string of :class:`argparse.HelpFormatter` states
112 Only the name of this class is considered a public API.
113 All the methods provided by the class are considered an implementation detail.
115 Therefore I may be forced to change the methods' signatures if :class:`argparse.HelpFormatter` is changed.
116 But I hope that I can keep the class attributes backward compatible so that you can create your own formatter class
117 by subclassing this class and changing the values of the class variables.
119 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.
120 '''
122 #: Wrap lines so that they are no longer than this number of characters.
123 max_width = 70
125 #: This value is assigned to :attr:`textwrap.TextWrapper.break_long_words`. This defaults to False to prevent URLs from breaking.
126 break_long_words = False
128 #: This value is assigned to :attr:`textwrap.TextWrapper.break_on_hyphens`. This defaults to False to prevent URLs from breaking.
129 break_on_hyphens = False
131 #: 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.
132 regex_linebreak = re.escape(r'\\') + '(?:\n|$)'
134 #: 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.
135 regex_list_item = '(?:^|\n)' + r'(\s*(?:[-+*!/.]|[0-9]+[.)])(?: \[[ x~]\])? )'
137 def __init__(self,
138 prog: str,
139 indent_increment: int = 2,
140 max_help_position: int = 24,
141 width: 'int|None' = None,
142 ) -> None:
143 '''
144 :param prog: The name of the program
145 :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.
146 '''
147 if width is None or width >= self.max_width:
148 width = self.max_width
149 super().__init__(prog, indent_increment, max_help_position, width)
152 # ------- override methods of parent class -------
154 def _fill_text(self, text: str, width: int, indent: str) -> str:
155 '''
156 This method joins the lines returned by :meth:`~confattr.utils.HelpFormatter._split_lines`.
158 This method is used to format text blocks such as the description.
159 It is *not* used to format the help of arguments—see :meth:`~confattr.utils.HelpFormatter._split_lines` for that.
160 '''
161 return '\n'.join(self._replace_nbsp(ln) for ln in self._split_lines(text, width, indent=indent, replace_nbsp=False))
163 def _split_lines(self, text: str, width: int, *, indent: str = '', replace_nbsp: bool = True) -> 'list[str]':
164 '''
165 This method cleans :paramref:`~confattr.utils.HelpFormatter._split_lines.text` with :func:`inspect.cleandoc` and
166 wraps the lines with :meth:`textwrap.TextWrapper.wrap`.
167 Paragraphs separated by an empty line are kept as separate paragraphs.
169 This method is used to format the help of arguments and
170 indirectly through :meth:`~confattr.utils.HelpFormatter._fill_text` to format text blocks such as description.
172 :param text: The text to be formatted
173 :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.)
174 :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`.
175 '''
176 lines = []
177 # The original implementation does not use cleandoc
178 # it simply gets rid of all indentation and line breaks with
179 # self._whitespace_matcher.sub(' ', text).strip()
180 # https://github.com/python/cpython/blob/main/Lib/argparse.py
181 text = inspect.cleandoc(text)
182 wrapper = textwrap.TextWrapper(width=width,
183 break_long_words=self.break_long_words, break_on_hyphens=self.break_on_hyphens)
184 for par in re.split('\n\\s*\n', text):
185 for ln in re.split(self.regex_linebreak, par):
186 wrapper.initial_indent = indent
187 wrapper.subsequent_indent = indent
188 pre_bullet_items = re.split(self.regex_list_item, ln)
189 lines.extend(wrapper.wrap(pre_bullet_items[0]))
190 for i in range(1, len(pre_bullet_items), 2):
191 bullet = pre_bullet_items[i]
192 item = pre_bullet_items[i+1]
193 add_indent = ' ' * len(bullet)
194 wrapper.initial_indent = indent + bullet
195 wrapper.subsequent_indent = indent + add_indent
196 item = item.replace('\n'+add_indent, '\n')
197 lines.extend(wrapper.wrap(item))
198 lines.append('')
200 lines = lines[:-1]
202 if replace_nbsp:
203 lines = [self._replace_nbsp(ln) for ln in lines]
205 return lines
207 @staticmethod
208 def _replace_nbsp(ln: str) -> str:
209 return ln.replace(' ', ' ')
213if typing.TYPE_CHECKING:
214 class HelpFormatterKwargs(typing.TypedDict, total=False):
215 prog: str
216 indent_increment: int
217 max_help_position: int
218 width: int
221class HelpFormatterWrapper:
223 '''
224 The doc string of :class:`argparse.HelpFormatter` states:
226 Only the name of this class is considered a public API.
227 All the methods provided by the class are considered an implementation detail.
229 This is a wrapper which tries to stay backward compatible even if :class:`argparse.HelpFormatter` changes.
230 '''
232 def __init__(self, formatter_class: 'type[argparse.HelpFormatter]', **kw: 'Unpack[HelpFormatterKwargs]') -> None:
233 '''
234 :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`)
235 :param prog: The name of the program
236 :param indent_increment: The number of spaces by which to indent the contents of a section
237 :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.
238 :param width: Maximal number of characters per line
239 '''
240 kw.setdefault('prog', '')
241 self.formatter = formatter_class(**kw)
244 # ------- format directly -------
246 def format_text(self, text: str) -> str:
247 '''
248 Format a text and return it immediately without adding it to :meth:`~confattr.utils.HelpFormatterWrapper.format_help`.
249 '''
250 return self.formatter._format_text(text)
252 def format_item(self, bullet: str, text: str) -> str:
253 '''
254 Format a list item and return it immediately without adding it to :meth:`~confattr.utils.HelpFormatterWrapper.format_help`.
255 '''
256 # apply section indentation
257 bullet = ' ' * self.formatter._current_indent + bullet
258 width = max(self.formatter._width - self.formatter._current_indent, 11)
260 # _fill_text does not distinguish between textwrap's initial_indent and subsequent_indent
261 # instead I am using bullet for both and then replace the bullet with whitespace on all but the first line
262 text = self.formatter._fill_text(text, width, bullet)
263 pattern_bullet = '(?<=\n)' + re.escape(bullet)
264 indent = ' ' * len(bullet)
265 text = re.sub(pattern_bullet, indent, text)
266 return text + '\n'
269 # ------- input -------
271 def add_start_section(self, heading: str) -> None:
272 '''
273 Start a new section.
275 This influences the formatting of following calls to :meth:`~confattr.utils.HelpFormatterWrapper.add_text` and :meth:`~confattr.utils.HelpFormatterWrapper.add_item`.
277 You can call this method again before calling :meth:`~confattr.utils.HelpFormatterWrapper.add_end_section` to create a subsection.
278 '''
279 self.formatter.start_section(heading)
281 def add_end_section(self) -> None:
282 '''
283 End the last section which has been started with :meth:`~confattr.utils.HelpFormatterWrapper.add_start_section`.
284 '''
285 self.formatter.end_section()
287 def add_text(self, text: str) -> None:
288 '''
289 Add some text which will be formatted when calling :meth:`~confattr.utils.HelpFormatterWrapper.format_help`.
290 '''
291 self.formatter.add_text(text)
293 def add_start_list(self) -> None:
294 '''
295 Start a new list which can be filled with :meth:`~confattr.utils.HelpFormatterWrapper.add_item`.
296 '''
297 # nothing to do, this exists only as counter piece for add_end_list
299 def add_item(self, text: str, bullet: str = '- ') -> None:
300 '''
301 Add a list item which will be formatted when calling :meth:`~confattr.utils.HelpFormatterWrapper.format_help`.
302 A list must be started with :meth:`~confattr.utils.HelpFormatterWrapper.add_start_list` and ended with :meth:`~confattr.utils.HelpFormatterWrapper.add_end_list`.
303 '''
304 self.formatter._add_item(self.format_item, (bullet, text))
306 def add_end_list(self) -> None:
307 '''
308 End a list. This must be called after the last :meth:`~confattr.utils.HelpFormatterWrapper.add_item`.
309 '''
310 def identity(x: str) -> str:
311 return x
312 self.formatter._add_item(identity, ('\n',))
314 # ------- output -------
316 def format_help(self) -> str:
317 '''
318 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`.
319 '''
320 return self.formatter.format_help()
323# ---------- argparse actions ----------
325class CallAction(argparse.Action):
327 def __init__(self, option_strings: 'Sequence[str]', dest: str, callback: 'Callable[[], None]', help: 'str|None' = None, nargs: 'int|str' = 0) -> None:
328 if help is None:
329 if callback.__doc__ is None:
330 raise TypeError("missing doc string for function %s" % callback.__name__)
331 help = callback.__doc__.strip()
332 argparse.Action.__init__(self, option_strings, dest, nargs=nargs, help=help)
333 self.callback = callback
335 def __call__(self, parser: argparse.ArgumentParser, namespace: argparse.Namespace, values: object, option_string: 'str|None' = None) -> None:
336 self.callback(*values)