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

14 from pygeodesy.errors import _AssertionError, _AttributeError, \

15 _xcallable, _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__ = '24.05.26'

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 _xcallable(getter=method, fget=fget)

161

162 self.method = method

163 self.name = method.__name__

164 d = doc or method.__doc__

165 if _FOR_DOCS and d:

166 self.__doc__ = d # PYCHOK no cover

167

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

169

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

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

172 '''

173 if farg:

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

175 n = _SPACE_(n, farg.__name__)

176 else:

177 n = nameter

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

179 return _AttributeError(e, txt=n)

180

181 def _fdel(self, inst):

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

183 '''

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

185

186 def _fget(self, inst):

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

188 '''

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

190 return inst.__dict__[self.name]

191 except KeyError:

192 # cache the value in the instance' __dict__

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

194 return val

195

196 def _fset_error(self, inst, val):

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

198 '''

199 n = _MODS.named.classname(inst)

200 n = _DOT_(n, self.name)

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

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

203

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

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

206 '''

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

208

209 def _update_from(self, inst, other):

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

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

212 '''

213 n = self.name # name, NOT _name

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

215 if v is MISSING:

216 inst.__dict__.pop(n, None)

217 else:

218 inst.__dict__[n] = v

219

220 def deleter(self, fdel):

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

222 '''

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

224

225 def getter(self, fget):

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

227 '''

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

229

230 def setter(self, fset):

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

232 '''

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

234

235

236 class Property_RO(_PropertyBase):

237 # No __doc__ on purpose

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

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

240 to be used as C{decorator}.

241

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

243 to be invoked only once.

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

245

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

247 a more descriptive error message when set.

248

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

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

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

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

253

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

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

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

257 '''

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

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

260

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

262 if inst is None:

263 return self

264 try: # to get the cached value immediately

265 return inst.__dict__[self.name]

266 except (AttributeError, KeyError):

267 return self._fget(inst)

268

269

270 class Property(Property_RO):

271 # No __doc__ on purpose

272 __init__ = Property_RO.__init__

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

274 to be used as C{decorator}.

275

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

277

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

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

280 '''

281

282 def setter(self, method):

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

284

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

286

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

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

289 '''

290 def _fset(inst, val):

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

292 '''

293 _ = method(inst, val)

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

295

296 return self._setters(method, _fset)

297

298 def setter_(self, method):

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

300

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

302 and returning the new property value to be I{cached} or

303 I{memoized}.

304 '''

305 def _fset(inst, val):

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

307 '''

308 val = method(inst, val)

309 inst.__dict__[self.name] = val

310

311 return self._setters(method, _fset)

312

313 def _setters(self, method, _fset):

314 _xcallable(setter=method, fset=_fset)

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

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

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

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

319 return self

320

321

322 class property_RO(_PropertyBase):

323 # No __doc__ on purpose

324 _uname = NN

325

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

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

328

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

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

331

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

333 a more descriptive error message when set.

334

335 @see: L{Property_RO}.

336 '''

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

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

339

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

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

342 '''

343 uname = self._uname

344 if uname in inst.__dict__:

345 if Clas: # overrides inst.__class__

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

347 else:

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

349# if d is MISSING: # XXX superfluous

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

351# if uname in c.__dict__:

352# d = c.__dict__[uname]

353# break

354 if d is None: # remove inst value

355 inst.__dict__.pop(uname)

356

357

358 class _NamedProperty(property):

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

360 '''

361 @Property_RO

362 def name(self):

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

364 '''

365 return self.fget.__name__

366

367

368 def property_doc_(doc):

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

370

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

372

373 @example:

374

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

376 >>> def name(self):

377 >>> ...

378 >>>

379 >>> @name.setter

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

381 >>> ...

382 '''

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

384 # 2016 p. 212+, 2022 p. 331+, Example 9-22 and <https://

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

386

387 def _documented_property(method):

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

389 '''

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

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

392

393 return _documented_property

394

395

396 def _deprecated(call, kind, qual_d):

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

398

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

400 Addison-Wesley, 2019.

401 '''

402 doc = _docof(call)

403

404 @_wraps(call) # PYCHOK self?

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

406 if qual_d: # function

407 q = qual_d

408 elif args: # method

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

410 else: # PYCHOK no cover

411 q = call.__name__

412 _throwarning(kind, q, doc)

413 return call(*args, **kwds)

414

415 return _deprecated_call

416

417

418 def deprecated_class(cls_or_class):

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

420

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

422

423 @note: NOT a decorator!

424 '''

425 if _WARNINGS_X_DEV:

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

427 _throwarning(_class_, q, cls_or_class.__doc__)

428

429

430 def deprecated_function(call):

431 '''Decorator for a DEPRECATED function.

432

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

434

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

436 '''

437 return _deprecated(call, _function_, _DOT_(

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

439 _WARNINGS_X_DEV else call

440

441

442 def deprecated_method(call):

443 '''Decorator for a DEPRECATED method.

444

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

446

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

448 '''

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

450

451

452 def _deprecated_module(name): # PYCHOK no cover

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

454 '''

455 if _WARNINGS_X_DEV:

456 _throwarning(_module_, name, _dont_use_)

457

458

459 if _WARNINGS_X_DEV:

460 class deprecated_property(_PropertyBase):

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

462 '''

463 def __init__(self, method):

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

465 '''

466 doc = _docof(method)

467

468 def _fget(inst): # PYCHOK no cover

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

470 '''

471 q = _qualified(inst, self.name)

472 _throwarning(property.__name__, q, doc)

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

474

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

476

477 def setter(self, method):

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

479

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

481

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

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

484 '''

485 if not callable(method):

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

487

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

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

490 else:

491

492 def _fset(inst, val):

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

494 '''

495 q = _qualified(inst, self.name)

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

497 method(inst, val)

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

499

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

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

502 return self

503

504 else: # PYCHOK no cover

505 class deprecated_property(property): # PYCHOK expected

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

507 '''

508 pass

509

510 deprecated_Property = deprecated_property

511

512

513 def deprecated_Property_RO(method):

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

515

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

517

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

519 '''

520 return _deprecated_RO(method, Property_RO)

521

522

523 def deprecated_property_RO(method):

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

525

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

527

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

529 '''

530 return _deprecated_RO(method, property_RO)

531

532

533 def _deprecated_RO(method, _RO):

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

535 '''

536 doc = _docof(method)

537

538 if _WARNINGS_X_DEV:

539

540 class _Deprecated_RO(_PropertyBase):

541 __doc__ = doc

542

543 def __init__(self, method):

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

545

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

547 q = _qualified(inst, self.name)

548 _throwarning(_RO.__name__, q, doc)

549 return self.method(inst)

550

551 return _Deprecated_RO(method)

552 else: # PYCHOK no cover

553 return _RO(method, doc=doc)

554

555

556 def _docof(obj):

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

558 '''

559 try:

560 d = obj.__doc__.strip()

561 i = d.find(_DEPRECATED_)

562 except AttributeError:

563 i = -1

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

565

566

567 def _qualified(inst, name):

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

569 '''

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

571 c = inst.__class__

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

573 return q

574

575

576 class DeprecationWarnings(object):

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

578 '''

579 _Warnings = 0

580

581 def __call__(self): # for backward compatibility

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

583

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

585 far or C{None} if not enabled.

586

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

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

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

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

591 '''

592 return self.Warnings

593

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

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

596 '''

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

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

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

600 kwds = _xkwds(stacklevel, stacklevel=3)

601 # XXX invoke warn or raise DeprecationWarning(text)

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

603 self._Warnings += 1

604

605 @Property_RO

606 def _warn(self):

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

608 '''

609 from warnings import warn

610 return warn

611

612 @property_RO

613 def Warnings(self):

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

615 far or C{None} if not enabled.

616 '''

617 return self._Warnings if _WARNINGS_X_DEV else None

618

619 DeprecationWarnings = DeprecationWarnings() # PYCHOK singleton

620_throwarning = DeprecationWarnings.throw

621

622# **) MIT License

623#

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

625#

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

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

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

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

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

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

632#

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

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

635#

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

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

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

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

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

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

642# OTHER DEALINGS IN THE SOFTWARE.