Hide keyboard shortcuts

Hot-keys on this page

r m x p   toggle line displays

j k   next/prev highlighted chunk

0   (zero) top of page

1   (one) first highlighted chunk

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

362

363

364

365

366

367

368

369

370

371

372

373

374

375

376

377

378

379

380

381

382

383

384

385

386

387

388

389

390

391

392

393

394

395

396

397

398

399

400

401

402

403

404

405

406

407

408

409

410

411

412

413

414

415

416

417

418

419

420

421

422

423

424

425

426

427

428

429

430

431

432

433

434

435

436

437

438

439

440

441

442

443

444

445

446

447

448

449

450

451

452

453

454

455

456

457

458

459

460

461

462

463

464

465

466

467

468

469

470

471

472

473

474

475

476

477

478

479

480

 

# -*- coding: utf-8 -*- 

 

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

deprecation decorators. 

 

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

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

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

choices, see function L{DeprecationWarnings} below. 

''' 

from pygeodesy.errors import _AssertionError, _AttributeError, \ 

_xkwds, _xkwds_get 

from pygeodesy.interns import NN, _DOT_, _EQUALSPACED_, _immutable_, \ 

_invalid_, MISSING, _N_A_, _NL_NL_, \ 

_SPACE_, _UNDER_ 

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

_FOR_DOCS, _PYTHON_X_DEV, _sys 

 

from functools import wraps as _wraps 

 

__all__ = _ALL_LAZY.props 

__version__ = '22.04.27' 

 

_DEPRECATED_ = 'DEPRECATED' 

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

_has_been_ = 'has been' 

_Warnings = 0 

_W_DEV = (bool(_sys.warnoptions) or _PYTHON_X_DEV) \ 

and _getenv('PYGEODESY_WARNINGS', NN) 

 

 

def _hasProperty(inst, name, *Classes): 

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

''' 

ps = Classes if Classes else _PropertyBase 

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

p = c.__dict__.get(name, None) 

if isinstance(p, ps) and p.name == name: 

return True 

return False 

 

 

def _update_all(inst, *attrs, **Base): 

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

and the named C{attrs} from an instance' C{__dict__}. 

 

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

''' 

try: 

d = inst.__dict__ 

except AttributeError: 

d = {} 

u = len(d) 

if u: 

try: 

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

B = _xkwds_get(Base, Base=_PropertyBase) 

except AttributeError: 

S = () 

for C in S: # class and super classes 

for n, p in C.__dict__.items(): 

if n in d and isinstance(p, B) and p.name == n: 

p._update(inst, C) 

p = d.pop # remove specified attributes 

for a in attrs: # PYCHOK no cover 

if hasattr(inst, a): 

p(a, None) 

else: 

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

a = _DOT_(n, _SPACE_(a, _invalid_)) 

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

u -= len(d) 

return u # updated 

 

 

class _PropertyBase(property): 

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

''' 

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

 

if not callable(method): 

self.getter(method) # PYCHOK no cover 

 

self.method = method 

self.name = method.__name__ 

d = doc or method.__doc__ 

if _FOR_DOCS and d: 

self.__doc__ = d # PYCHOK no cover 

 

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

 

def _fdel(self, inst): 

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

''' 

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

 

def _fget(self, inst): 

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

''' 

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

return inst.__dict__[self.name] 

except KeyError: 

# cache the value in the instance' __dict__ 

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

return val 

 

def _fset_error(self, inst, val): 

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

''' 

n = _MODS.named.classname(inst) 

n = _DOT_(n, self.name) 

n = _EQUALSPACED_(n, repr(val)) 

raise self._Error(_immutable_, n, None) 

 

def _update(self, inst, *unused): 

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

''' 

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

 

def _update_from(self, inst, other): 

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

if present, otherwise zap it. 

''' 

n = self.name # name, NOT _name 

v = other.__dict__.get(n, MISSING) 

if v is MISSING: 

inst.__dict__.pop(n, None) 

else: 

inst.__dict__[n] = v 

 

def deleter(self, fdel): 

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

''' 

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

 

def getter(self, fget): 

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

''' 

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

 

def setter(self, fset): 

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

''' 

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

 

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

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

''' 

if farg: 

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

n = _SPACE_(n, farg.__name__) 

else: 

n = nameter 

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

return _AttributeError(e, txt=n) 

 

 

class Property_RO(_PropertyBase): 

# No __doc__ on purpose 

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

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

to be used as C{decorator}. 

 

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

to be invoked only once. 

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

 

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

a more descriptive error message when set. 

 

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

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

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

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

 

@see: Luciano Ramalho, "Fluent Python", page 636, O'Reilly, 2016, 

"Coding a Property Factory", especially Example 19-24 and U{class 

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

''' 

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

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

 

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

if inst is None: 

return self 

try: # to get the cached value immediately 

return inst.__dict__[self.name] 

except (AttributeError, KeyError): 

return self._fget(inst) 

 

 

class Property(Property_RO): 

# No __doc__ on purpose 

__init__ = Property_RO.__init__ 

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

to be used as C{decorator}. 

 

@see: L{Property_RO} for more details. 

 

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

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

''' 

 

def setter(self, method): 

'''Make this C{Property} I{mutable}. 

 

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

 

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

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

''' 

if not callable(method): 

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

 

if _FOR_DOCS: # XXX force method.__doc__ into epydoc 

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

else: 

 

def _fset(inst, val): 

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

''' 

method(inst, val) 

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

 

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

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

return self 

 

 

class property_RO(_PropertyBase): 

# No __doc__ on purpose 

_uname = NN 

 

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

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

 

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

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

 

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

a more descriptive error message when set. 

 

@see: L{Property_RO}. 

''' 

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

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

 

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

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

''' 

uname = self._uname 

if uname in inst.__dict__: 

if Clas: # overrides inst.__class__ 

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

else: 

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

# if d is MISSING: # XXX superfluous 

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

# if uname in c.__dict__: 

# d = c.__dict__[uname] 

# break 

if d is None: # remove inst value 

inst.__dict__.pop(uname) 

 

 

class _NamedProperty(property): 

'''(INTERNAL) Class C{property} with retrievable name. 

''' 

@Property_RO 

def name(self): 

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

''' 

return self.fget.__name__ 

 

 

def property_doc_(doc): 

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

 

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

 

@example: 

 

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

>>> def name(self): 

>>> ... 

>>> 

>>> @name.setter 

>>> def name(self, value): 

>>> ... 

''' 

# See Luciano Ramalho, "Fluent Python", page 212ff, O'Reilly, 2016, 

# "Parameterized Decorators", especially Example 7-23. Also, see 

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

 

def _documented_property(method): 

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

''' 

t = 'get and set' if doc.startswith(_SPACE_) else NN 

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

 

return _documented_property 

 

 

def _deprecated(call, kind, qual_d): 

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

 

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

Addison-Wesley, 2019. 

''' 

doc = _docof(call) 

 

@_wraps(call) # PYCHOK self? 

def _deprecated_call(*args, **kwds): 

if qual_d: # function 

q = qual_d 

elif args: # method 

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

else: # PYCHOK no cover 

q = call.__name__ 

_throwarning(kind, q, doc) 

return call(*args, **kwds) 

 

return _deprecated_call 

 

 

def deprecated_class(cls_or_class): 

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

 

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

 

@note: NOT a decorator! 

''' 

if _W_DEV: 

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

_throwarning('class', q, cls_or_class.__doc__) 

 

 

def deprecated_function(call): 

'''Decorator for a DEPRECATED function. 

 

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

 

@return: The B{C{call}} DEPRECATED. 

''' 

return _deprecated(call, 'function', _DOT_( 

call.__module__, call.__name__)) if \ 

_W_DEV else call 

 

 

def deprecated_method(call): 

'''Decorator for a DEPRECATED method. 

 

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

 

@return: The B{C{call}} DEPRECATED. 

''' 

return _deprecated(call, 'method', NN) if _W_DEV else call 

 

 

def _deprecated_module(name): # PYCHOK no cover 

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

''' 

if _W_DEV: 

_throwarning('module', name, _dont_use_) 

 

 

def deprecated_Property_RO(method): 

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

 

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

 

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

''' 

return _deprecated_RO(method, Property_RO) 

 

 

def deprecated_property_RO(method): 

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

 

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

 

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

''' 

return _deprecated_RO(method, property_RO) 

 

 

def _deprecated_RO(method, _RO): 

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

''' 

doc = _docof(method) 

 

if _W_DEV: 

 

class _Deprecated_RO(_PropertyBase): 

__doc__ = doc 

 

def __init__(self, method): 

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

 

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

q = _qualified(inst, self.name) 

_throwarning(_RO.__name__, q, doc) 

return self.method(inst) 

 

return _Deprecated_RO(method) 

else: # PYCHOK no cover 

return _RO(method, doc=doc) 

 

 

def DeprecationWarnings(): 

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

 

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

far or C{None} if not enabled. 

 

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

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

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

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

''' 

return _Warnings if _W_DEV else None 

 

 

def _docof(obj): 

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

''' 

try: 

d = obj.__doc__.strip() 

i = d.find(_DEPRECATED_) 

except AttributeError: 

i = -1 

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

 

 

def _qualified(inst, name): 

'''(INTERNAL) Fully qualify a name. 

''' 

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

c = inst.__class__ 

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

return q 

 

 

def _throwarning(kind, name, doc, **stacklevel): # stacklevel=3 

'''(INTERNAL) Report or raise a C{DeprecationWarning}. 

''' 

from warnings import warn 

 

line = doc.split(_NL_NL_, 1)[0].split() 

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

text = _SPACE_(kind, name, _has_been_, *line) 

kwds = _xkwds(stacklevel, stacklevel=3) 

# XXX invoke warn or raise DeprecationWarning(text) 

warn(text, category=DeprecationWarning, **kwds) 

 

global _Warnings 

_Warnings += 1 

 

# **) MIT License 

# 

# Copyright (C) 2016-2022 -- mrJean1 at Gmail -- All Rights Reserved. 

# 

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

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

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

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

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

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

# 

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

# in all copies or substantial portions of the Software. 

# 

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

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

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

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

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

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

# OTHER DEALINGS IN THE SOFTWARE.