1

2# -*- coding: utf-8 -*-

3

4 u'''Mutable, immutable and caching/memoizing properties and

5 deprecation decorators.

6

7 To enable C{DeprecationWarning}s from C{PyGeodesy}, set env var

8 C{PYGEODESY_WARNINGS} to a non-empty string I{AND} run C{python}

9 with command line option C{-X dev} or with one of the C{-W}

10 choices, see callable L{DeprecationWarnings} below.

11'''

12

13 from pygeodesy.basics import isclass as _isclass # _MODS

14 from pygeodesy.errors import _AssertionError, _AttributeError, \

15 _xkwds, _xkwds_get

16 from pygeodesy.interns import MISSING, NN, _an_, _COMMASPACE_, \

17 _DEPRECATED_, _DOT_, _EQUALSPACED_, \

18 _immutable_, _invalid_, _module_, _N_A_, \

19 _not_, _SPACE_, _UNDER_, _DNL_ # PYCHOK used!

20# from pygeodesy.named import callname # _MODS, avoid circular

21 from pygeodesy.lazily import _ALL_LAZY, _ALL_MODS as _MODS, \

22 _FOR_DOCS, _WARNINGS_X_DEV

23# from pygeodesy.streprs import Fmt # _MODS

24

25 from functools import wraps as _wraps

26

27__all__ = _ALL_LAZY.props

28__version__ = '24.05.12'

29

30_class_ = 'class'

31_dont_use_ = _DEPRECATED_ + ", don't use."

32_function_ = 'function'

33_get_and_set_ = 'get and set'

34_has_been_ = 'has been' # PYCHOK used!

35_method_ = 'method'

36_not_an_inst_ = _not_(_an_, 'instance')

37

38

39 def _allPropertiesOf(Clas_or_inst, *Bases, **excls):

40 '''(INTERNAL) Yield all C{R/property/_RO}s at C{Clas_or_inst}

41 as specified in the C{Bases} arguments, except C{excls}.

42 '''

43 if _isclass(Clas_or_inst):

44 S = Clas_or_inst, # just this Clas

45 else: # class and super-classes of inst

46 try:

47 S = Clas_or_inst.__class__.__mro__[:-1] # not object

48 except AttributeError:

49 raise

50 S = () # not an inst

51 B = Bases or _PropertyBase

52 _isa = isinstance

53 for C in S:

54 for n, p in C.__dict__.items():

55 if _isa(p, B) and p.name == n and n not in excls:

56 yield p

57

58

59 def _allPropertiesOf_n(n, Clas_or_inst, *Bases, **excls):

60 '''(INTERNAL) Assert the number of C{R/property/_RO}s at C{Clas_or_inst}.

61 '''

62 t = tuple(p.name for p in _allPropertiesOf(Clas_or_inst, *Bases, **excls))

63 if len(t) != n:

64 raise _AssertionError(_COMMASPACE_.join(t), Clas_or_inst,

65 txt=_COMMASPACE_(len(t), _not_(n)))

66 return t

67

68

69 def _hasProperty(inst, name, *Classes): # in .named._NamedBase._update

70 '''(INTERNAL) Check whether C{inst} has a C{P/property/_RO} by this C{name}.

71 '''

72 p = getattr(inst.__class__, name, None) # walks __class__.__mro__

73 return bool(p and isinstance(p, Classes or _PropertyBase)

74 and p.name == name)

75

76

77# def _isclass(obj):

78# '''(INTERNAL) Get and overwrite C{_isclass}.

79# '''

80# _MODS.getmodule(__name__)._isclass = f = _MODS.basics.isclass

81# return f(obj)

82

83

84 def _update_all(inst, *attrs, **Base_needed):

85 '''(INTERNAL) Zap all I{cached} L{property_RO}s, L{Property}s,

86 L{Property_RO}s and the named C{attrs} of an instance.

87

88 @return: The number of updates (C{int}), if any.

89 '''

90 if _isclass(inst):

91 raise _AssertionError(inst, txt=_not_an_inst_)

92 try:

93 d = inst.__dict__

94 except AttributeError:

95 return 0

96 u = len(d)

97 if u > _xkwds_get(Base_needed, needed=0):

98 B = _xkwds_get(Base_needed, Base=_PropertyBase)

99 for p in _allPropertiesOf(inst, B):

100 p._update(inst) # d.pop(p.name, None)

101

102 if attrs:

103 _update_attrs(inst, *attrs) # remove attributes from inst.__dict__

104 u -= len(d)

105 return u # updates

106

107

108# def _update_all_from(inst, other, **Base):

109# '''(INTERNAL) Update all I{cached} L{Property}s and

110# L{Property_RO}s of instance C{inst} from C{other}.

111#

112# @return: The number of updates (C{int}), if any.

113# '''

114# if _isclass(inst):

115# raise _AssertionError(inst, txt=_not_an_inst_)

116# try:

117# d = inst.__dict__

118# f = other.__dict__

119# except AttributeError:

120# return 0

121# u = len(f)

122# if u:

123# u = len(d)

124# B = _xkwds_get(Base, Base=_PropertyBase)

125# for p in _allPropertiesOf(inst, B):

126# p._update_from(inst, other)

127# u -= len(d)

128# return u # number of updates

129

130

131 def _update_attrs(inst, *attrs):

132 '''(INTERNAL) Zap all named C{attrs} of an instance.

133

134 @return: The number of updates (C{int}), if any.

135 '''

136 try:

137 d = inst.__dict__

138 except AttributeError:

139 return 0

140 u = len(d)

141 if u: # zap attrs from inst.__dict__

142 _p = d.pop

143 for a in attrs:

144 _ = _p(a, MISSING)

145# if _ is MISSING and not hasattr(inst, a):

146# n = _MODS.named.classname(inst, prefixed=True)

147# a = _DOT_(n, _SPACE_(a, _invalid_))

148# raise _AssertionError(a, txt=repr(inst))

149# _ = _p(a, None) # redo: hasattr side effect

150 u -= len(d)

151 # assert u >= 0

152 return u # number of named C{attrs} zapped

153

154

155 class _PropertyBase(property):

156 '''(INTERNAL) Base class for C{P/property/_RO}.

157 '''

158 def __init__(self, method, fget, fset, doc=NN):

159

160 if not callable(method):

161 self.getter(method) # PYCHOK no cover

162

163 self.method = method

164 self.name = method.__name__

165 d = doc or method.__doc__

166 if _FOR_DOCS and d:

167 self.__doc__ = d # PYCHOK no cover

168

169 property.__init__(self, fget, fset, self._fdel, d or _N_A_)

170

171 def _Error(self, kind, nameter, farg):

172 '''(INTERNAL) Return an C{AttributeError} instance.

173 '''

174 if farg:

175 n = _DOT_(self.name, nameter.__name__)

176 n = _SPACE_(n, farg.__name__)

177 else:

178 n = nameter

179 e = _SPACE_(kind, _MODS.named.classname(self))

180 return _AttributeError(e, txt=n)

181

182 def _fdel(self, inst):

183 '''Zap the I{cached/memoized} C{property} value.

184 '''

185 self._update(inst, None) # PYCHOK no cover

186

187 def _fget(self, inst):

188 '''Get and I{cache/memoize} the C{property} value.

189 '''

190 try: # to get the value cached in instance' __dict__

191 return inst.__dict__[self.name]

192 except KeyError:

193 # cache the value in the instance' __dict__

194 inst.__dict__[self.name] = val = self.method(inst)

195 return val

196

197 def _fset_error(self, inst, val):

198 '''Throws an C{AttributeError}, always.

199 '''

200 n = _MODS.named.classname(inst)

201 n = _DOT_(n, self.name)

202 n = _EQUALSPACED_(n, repr(val))

203 raise self._Error(_immutable_, n, None)

204

205 def _update(self, inst, *unused):

206 '''(INTERNAL) Zap the I{cached/memoized} C{inst.__dict__[name]} item.

207 '''

208 inst.__dict__.pop(self.name, None) # name, NOT _name

209

210 def _update_from(self, inst, other):

211 '''(INTERNAL) Copy a I{cached/memoized} C{inst.__dict__[name]} item

212 from C{other.__dict__[name]} if present, otherwise zap it.

213 '''

214 n = self.name # name, NOT _name

215 v = other.__dict__.get(n, MISSING)

216 if v is MISSING:

217 inst.__dict__.pop(n, None)

218 else:

219 inst.__dict__[n] = v

220

221 def deleter(self, fdel):

222 '''Throws an C{AttributeError}, always.

223 '''

224 raise self._Error(_invalid_, self.deleter, fdel)

225

226 def getter(self, fget):

227 '''Throws an C{AttributeError}, always.

228 '''

229 raise self._Error(_invalid_, self.getter, fget)

230

231 def setter(self, fset):

232 '''Throws an C{AttributeError}, always.

233 '''

234 raise self._Error(_immutable_, self.setter, fset)

235

236

237 class Property_RO(_PropertyBase):

238 # No __doc__ on purpose

239 def __init__(self, method, doc=NN): # PYCHOK expected

240 '''New I{immutable}, I{caching}, I{memoizing} C{property} I{Factory}

241 to be used as C{decorator}.

242

243 @arg method: The callable being decorated as this C{property}'s C{getter},

244 to be invoked only once.

245 @kwarg doc: Optional property documentation (C{str}).

246

247 @note: Like standard Python C{property} without a C{setter}, but with

248 a more descriptive error message when set.

249

250 @see: Python 3's U{functools.cached_property<https://docs.Python.org/3/

251 library/functools.html#functools.cached_property>} and U{-.cache

252 <https://Docs.Python.org/3/library/functools.html#functools.cache>}

253 to I{cache} or I{memoize} the property value.

254

255 @see: Luciano Ramalho, "Fluent Python", O'Reilly, Example 19-24, 2016

256 p. 636 or Example 22-28, 2022 p. 870 and U{class Property

257 <https://docs.Python.org/3/howto/descriptor.html>}.

258 '''

259 _fget = method if _FOR_DOCS else self._fget # XXX force method.__doc__ to epydoc

260 _PropertyBase.__init__(self, method, _fget, self._fset_error)

261

262 def __get__(self, inst, *unused): # PYCHOK 2 vs 3 args

263 if inst is None:

264 return self

265 try: # to get the cached value immediately

266 return inst.__dict__[self.name]

267 except (AttributeError, KeyError):

268 return self._fget(inst)

269

270

271 class Property(Property_RO):

272 # No __doc__ on purpose

273 __init__ = Property_RO.__init__

274 '''New I{mutable}, I{caching}, I{memoizing} C{property} I{Factory}

275 to be used as C{decorator}.

276

277 @see: L{Property_RO} for more details.

278

279 @note: Unless and until the C{setter} is defined, this L{Property} behaves

280 like an I{immutable}, I{caching}, I{memoizing} L{Property_RO}.

281 '''

282

283 def setter(self, method):

284 '''Make this C{Property} I{mutable}.

285

286 @arg method: The callable being decorated as this C{Property}'s C{setter}.

287

288 @note: Setting a new property value always clears the previously I{cached}

289 or I{memoized} value I{after} invoking the B{C{method}}.

290 '''

291 if not callable(method):

292 _PropertyBase.setter(self, method) # PYCHOK no cover

293

294 if _FOR_DOCS: # XXX force method.__doc__ into epydoc

295 _PropertyBase.__init__(self, self.method, self.method, method)

296 else:

297

298 def _fset(inst, val):

299 '''Set and I{cache}, I{memoize} the C{property} value.

300 '''

301 method(inst, val)

302 self._update(inst) # un-cache this item

303

304 # class Property <https://docs.Python.org/3/howto/descriptor.html>

305 _PropertyBase.__init__(self, self.method, self._fget, _fset)

306 return self

307

308

309 class property_RO(_PropertyBase):

310 # No __doc__ on purpose

311 _uname = NN

312

313 def __init__(self, method, doc=NN): # PYCHOK expected

314 '''New I{immutable}, standard C{property} to be used as C{decorator}.

315

316 @arg method: The callable being decorated as C{property}'s C{getter}.

317 @kwarg doc: Optional property documentation (C{str}).

318

319 @note: Like standard Python C{property} without a setter, but with

320 a more descriptive error message when set.

321

322 @see: L{Property_RO}.

323 '''

324 _PropertyBase.__init__(self, method, method, self._fset_error, doc=doc)

325 self._uname = NN(_UNDER_, self.name) # actual attr UNDER<name>

326

327 def _update(self, inst, *Clas): # PYCHOK signature

328 '''(INTERNAL) Zap the I{cached} C{B{inst}.__dict__[_name]} item.

329 '''

330 uname = self._uname

331 if uname in inst.__dict__:

332 if Clas: # overrides inst.__class__

333 d = Clas[0].__dict__.get(uname, MISSING)

334 else:

335 d = getattr(inst.__class__, uname, MISSING)

336# if d is MISSING: # XXX superfluous

337# for c in inst.__class__.__mro__[:-1]:

338# if uname in c.__dict__:

339# d = c.__dict__[uname]

340# break

341 if d is None: # remove inst value

342 inst.__dict__.pop(uname)

343

344

345 class _NamedProperty(property):

346 '''Class C{property} with retrievable name.

347 '''

348 @Property_RO

349 def name(self):

350 '''Get the name of this C{property} (C{str}).

351 '''

352 return self.fget.__name__

353

354

355 def property_doc_(doc):

356 '''Decorator for a standard C{property} with basic documentation.

357

358 @arg doc: The property documentation (C{str}).

359

360 @example:

361

362 >>> @property_doc_("documentation text.")

363 >>> def name(self):

364 >>> ...

365 >>>

366 >>> @name.setter

367 >>> def name(self, value):

368 >>> ...

369 '''

370 # See Luciano Ramalho, "Fluent Python", O'Reilly, Example 7-23,

371 # 2016 p. 212+, 2022 p. 331+, Example 9-22 and <https://

372 # Python-3-Patterns-Idioms-Test.ReadTheDocs.io/en/latest/PythonDecorators.html>

373

374 def _documented_property(method):

375 '''(INTERNAL) Return the documented C{property}.

376 '''

377 t = _get_and_set_ if doc.startswith(_SPACE_) else NN

378 return _NamedProperty(method, None, None, NN('Property to ', t, doc))

379

380 return _documented_property

381

382

383 def _deprecated(call, kind, qual_d):

384 '''(INTERNAL) Decorator for DEPRECATED functions, methods, etc.

385

386 @see: Brett Slatkin, "Effective Python", page 105, 2nd ed,

387 Addison-Wesley, 2019.

388 '''

389 doc = _docof(call)

390

391 @_wraps(call) # PYCHOK self?

392 def _deprecated_call(*args, **kwds):

393 if qual_d: # function

394 q = qual_d

395 elif args: # method

396 q = _qualified(args[0], call.__name__)

397 else: # PYCHOK no cover

398 q = call.__name__

399 _throwarning(kind, q, doc)

400 return call(*args, **kwds)

401

402 return _deprecated_call

403

404

405 def deprecated_class(cls_or_class):

406 '''Use inside __new__ or __init__ of a DEPRECATED class.

407

408 @arg cls_or_class: The class (C{cls} or C{Class}).

409

410 @note: NOT a decorator!

411 '''

412 if _WARNINGS_X_DEV:

413 q = _DOT_(cls_or_class.__module__, cls_or_class.__name__)

414 _throwarning(_class_, q, cls_or_class.__doc__)

415

416

417 def deprecated_function(call):

418 '''Decorator for a DEPRECATED function.

419

420 @arg call: The deprecated function (C{callable}).

421

422 @return: The B{C{call}} DEPRECATED.

423 '''

424 return _deprecated(call, _function_, _DOT_(

425 call.__module__, call.__name__)) if \

426 _WARNINGS_X_DEV else call

427

428

429 def deprecated_method(call):

430 '''Decorator for a DEPRECATED method.

431

432 @arg call: The deprecated method (C{callable}).

433

434 @return: The B{C{call}} DEPRECATED.

435 '''

436 return _deprecated(call, _method_, NN) if _WARNINGS_X_DEV else call

437

438

439 def _deprecated_module(name): # PYCHOK no cover

440 '''(INTERNAL) Callable within a DEPRECATED module.

441 '''

442 if _WARNINGS_X_DEV:

443 _throwarning(_module_, name, _dont_use_)

444

445

446 if _WARNINGS_X_DEV:

447 class deprecated_property(_PropertyBase):

448 '''Decorator for a DEPRECATED C{property} or C{Property}.

449 '''

450 def __init__(self, method):

451 '''Decorator for a DEPRECATED C{property} or C{Property} getter.

452 '''

453 doc = _docof(method)

454

455 def _fget(inst): # PYCHOK no cover

456 '''Get the C{property} or C{Property} value.

457 '''

458 q = _qualified(inst, self.name)

459 _throwarning(property.__name__, q, doc)

460 return self.method(inst) # == method

461

462 _PropertyBase.__init__(self, method, _fget, None, doc=doc)

463

464 def setter(self, method):

465 '''Decorator for a DEPRECATED C{property} or C{Property} setter.

466

467 @arg method: The callable being decorated as this C{Property}'s C{setter}.

468

469 @note: Setting a new property value always clears the previously I{cached}

470 or I{memoized} value I{after} invoking the B{C{method}}.

471 '''

472 if not callable(method):

473 _PropertyBase.setter(self, method) # PYCHOK no cover

474

475 if _FOR_DOCS: # XXX force method.__doc__ into epydoc

476 _PropertyBase.__init__(self, self.method, self.method, method)

477 else:

478

479 def _fset(inst, val):

480 '''Set the C{property} or C{Property} value.

481 '''

482 q = _qualified(inst, self.name)

483 _throwarning(property.__name__, q, _docof(method))

484 method(inst, val)

485 # self._update(inst) # un-cache this item

486

487 # class Property <https://docs.Python.org/3/howto/descriptor.html>

488 _PropertyBase.__init__(self, self.method, self._fget, _fset)

489 return self

490

491 else: # PYCHOK no cover

492 class deprecated_property(property): # PYCHOK expected

493 '''Decorator for a DEPRECATED C{property} or C{Property}.

494 '''

495 pass

496

497 deprecated_Property = deprecated_property

498

499

500 def deprecated_Property_RO(method):

501 '''Decorator for a DEPRECATED L{Property_RO}.

502

503 @arg method: The C{Property_RO.fget} method (C{callable}).

504

505 @return: The B{C{method}} DEPRECATED.

506 '''

507 return _deprecated_RO(method, Property_RO)

508

509

510 def deprecated_property_RO(method):

511 '''Decorator for a DEPRECATED L{property_RO}.

512

513 @arg method: The C{property_RO.fget} method (C{callable}).

514

515 @return: The B{C{method}} DEPRECATED.

516 '''

517 return _deprecated_RO(method, property_RO)

518

519

520 def _deprecated_RO(method, _RO):

521 '''(INTERNAL) Create a DEPRECATED C{property_RO} or C{Property_RO}.

522 '''

523 doc = _docof(method)

524

525 if _WARNINGS_X_DEV:

526

527 class _Deprecated_RO(_PropertyBase):

528 __doc__ = doc

529

530 def __init__(self, method):

531 _PropertyBase.__init__(self, method, self._fget, self._fset_error, doc=doc)

532

533 def _fget(self, inst): # PYCHOK no cover

534 q = _qualified(inst, self.name)

535 _throwarning(_RO.__name__, q, doc)

536 return self.method(inst)

537

538 return _Deprecated_RO(method)

539 else: # PYCHOK no cover

540 return _RO(method, doc=doc)

541

542

543 def _docof(obj):

544 '''(INTERNAL) Get uniform DEPRECATED __doc__ string.

545 '''

546 try:

547 d = obj.__doc__.strip()

548 i = d.find(_DEPRECATED_)

549 except AttributeError:

550 i = -1

551 return _DOT_(_DEPRECATED_, NN) if i < 0 else d[i:]

552

553

554 def _qualified(inst, name):

555 '''(INTERNAL) Fully qualify a name.

556 '''

557 # _DOT_(inst.classname, name), not _DOT_(inst.named4, name)

558 c = inst.__class__

559 q = _DOT_(c.__module__, c.__name__, name)

560 return q

561

562

563 class DeprecationWarnings(object):

564 '''(INTERNAL) Handle C{DeprecationWaring}s.

565 '''

566 _Warnings = 0

567

568 def __call__(self): # for backward compatibility

569 '''Have any C{DeprecationWarning}s been reported or raised?

570

571 @return: The number of C{DeprecationWarning}s (C{int}) so

572 far or C{None} if not enabled.

573

574 @note: To get C{DeprecationWarning}s if any, run C{python}

575 with env var C{PYGEODESY_WARNINGS} set to a non-empty

576 string I{AND} use C{python[3]} command line option

577 C{-X dev}, C{-W always} or C{-W error}, etc.

578 '''

579 return self.Warnings

580

581 def throw(self, kind, name, doc, **stacklevel): # stacklevel=3

582 '''Report or raise a C{DeprecationWarning}.

583 '''

584 line = doc.split(_DNL_, 1)[0].strip()

585 name = _MODS.streprs.Fmt.CURLY(L=name)

586 text = _SPACE_(kind, name, _has_been_, *line.split())

587 kwds = _xkwds(stacklevel, stacklevel=3)

588 # XXX invoke warn or raise DeprecationWarning(text)

589 self._warn(text, category=DeprecationWarning, **kwds)

590 self._Warnings += 1

591

592 @Property_RO

593 def _warn(self):

594 '''Get Python's C{warnings.warn}.

595 '''

596 from warnings import warn

597 return warn

598

599 @property_RO

600 def Warnings(self):

601 '''Get the number of C{DeprecationWarning}s (C{int}) so

602 far or C{None} if not enabled.

603 '''

604 return self._Warnings if _WARNINGS_X_DEV else None

605

606 DeprecationWarnings = DeprecationWarnings() # PYCHOK singleton

607_throwarning = DeprecationWarnings.throw

608

609# **) MIT License

610#

611# Copyright (C) 2016-2024 -- mrJean1 at Gmail -- All Rights Reserved.

612#

613# Permission is hereby granted, free of charge, to any person obtaining a

614# copy of this software and associated documentation files (the "Software"),

615# to deal in the Software without restriction, including without limitation

616# the rights to use, copy, modify, merge, publish, distribute, sublicense,

617# and/or sell copies of the Software, and to permit persons to whom the

618# Software is furnished to do so, subject to the following conditions:

619#

620# The above copyright notice and this permission notice shall be included

621# in all copies or substantial portions of the Software.

622#

623# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS

624# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

625# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

626# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR

627# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,

628# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR

629# OTHER DEALINGS IN THE SOFTWARE.