Coverage for .tox/cov/lib/python3.11/site-packages/confattr/utils.py: 100%
119 statements
« prev ^ index » next coverage.py v7.4.4, created at 2024-03-30 09:33 +0100
« prev ^ index » next coverage.py v7.4.4, created at 2024-03-30 09:33 +0100
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 As the doc string of :class:`argparse.HelpFormatter` states
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.
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.
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 '''
119 #: Wrap lines so that they are no longer than this number of characters.
120 max_width = 70
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
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
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|$)'
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]+[.)])(?: \[[ x~]\])? )'
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)
149 # ------- override methods of parent class -------
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`.
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))
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.
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.
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('')
197 lines = lines[:-1]
199 return lines
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
210class HelpFormatterWrapper:
212 '''
213 The doc string of :class:`argparse.HelpFormatter` states:
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.
218 This is a wrapper which tries to stay backward compatible even if :class:`argparse.HelpFormatter` changes.
219 '''
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)
233 # ------- format directly -------
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)
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)
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'
258 # ------- input -------
260 def add_start_section(self, heading: str) -> None:
261 '''
262 Start a new section.
264 This influences the formatting of following calls to :meth:`~confattr.utils.HelpFormatterWrapper.add_text` and :meth:`~confattr.utils.HelpFormatterWrapper.add_item`.
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)
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()
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)
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
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))
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',))
303 # ------- output -------
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()
312# ---------- argparse actions ----------
314class CallAction(argparse.Action):
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
324 def __call__(self, parser: argparse.ArgumentParser, namespace: argparse.Namespace, values: object, option_string: 'str|None' = None) -> None:
325 self.callback(*values)