Coverage for pygeodesy/props.py: 98%
207 statements
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2# -*- coding: utf-8 -*-
4u'''Mutable, immutable and caching/memoizing properties and
5deprecation decorators.
7To enable C{DeprecationWarning}s from C{PyGeodesy}, set env var
8C{PYGEODESY_WARNINGS} to a non-empty string I{AND} run C{python}
9with command line option C{-X dev} or with one of the C{-W}
10choices, see callable L{DeprecationWarnings} below.
11'''
13# from pygeodesy.basics import isclass # _MODS
14from pygeodesy.errors import _AssertionError, _AttributeError, \
15 _xkwds, _xkwds_get
16from 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
21from pygeodesy.lazily import _ALL_LAZY, _ALL_MODS as _MODS, \
22 _FOR_DOCS, _WARNINGS_X_DEV
23# from pygeodesy.streprs import Fmt # _MODS
25from functools import wraps as _wraps
27__all__ = _ALL_LAZY.props
28__version__ = '23.08.23'
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')
39def _allPropertiesOf(Clas_or_inst, *Bases):
40 '''(INTERNAL) Yield all C{R/property/_RO}s at C{Clas_or_inst}
41 as specified in the C{Bases} arguments.
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 for C in S:
53 for n, p in C.__dict__.items():
54 if isinstance(p, B) and p.name == n:
55 yield p
58def _allPropertiesOf_n(n, Clas_or_inst, *Bases):
59 '''(INTERNAL) Assert the number of C{R/property/_RO}s at C{Clas_or_inst}.
60 '''
61 t = tuple(p.name for p in _allPropertiesOf(Clas_or_inst, *Bases))
62 if len(t) != n:
63 raise _AssertionError(_COMMASPACE_.join(t), Clas_or_inst,
64 txt=_COMMASPACE_(len(t), _not_(n)))
65 return t
68def _hasProperty(inst, name, *Classes): # in .named._NamedBase._update
69 '''(INTERNAL) Check whether C{inst} has a C{P/property/_RO} by this C{name}.
70 '''
71 p = getattr(inst.__class__, name, None) # walks __class__.__mro__
72 return bool(p and isinstance(p, Classes or _PropertyBase)
73 and p.name == name)
76def _isclass(obj):
77 '''(INTERNAL) Get and overwrite C{_isclass}.
78 '''
79 f = _MODS.basics.isclass
80 # assert __name__.endswith('.props')
81 _MODS.props._isclass = f
82 return f(obj)
85def _update_all(inst, *attrs, **Base):
86 '''(INTERNAL) Zap all I{cached} L{property_RO}s, L{Property}s,
87 L{Property_RO}s and the named C{attrs} of an instance.
89 @return: The number of updates (C{int}), if any.
90 '''
91 if _isclass(inst):
92 raise _AssertionError(inst, txt=_not_an_inst_)
93 try:
94 d = inst.__dict__
95 except AttributeError:
96 return 0
97 u = len(d)
98 if u:
99 B = _xkwds_get(Base, Base=_PropertyBase)
100 for p in _allPropertiesOf(inst, B):
101 p._update(inst) # d.pop(p.name, None)
103 if attrs:
104 _update_attrs(inst, *attrs) # remove attributes from inst.__dict__
105 u -= len(d)
106 return u # updates
109# def _update_all_from(inst, other, **Base):
110# '''(INTERNAL) Update all I{cached} L{Property}s and
111# L{Property_RO}s of instance C{inst} from C{other}.
112#
113# @return: The number of updates (C{int}), if any.
114# '''
115# if _isclass(inst):
116# raise _AssertionError(inst, txt=_not_an_inst_)
117# try:
118# d = inst.__dict__
119# f = other.__dict__
120# except AttributeError:
121# return 0
122# u = len(f)
123# if u:
124# u = len(d)
125# B = _xkwds_get(Base, Base=_PropertyBase)
126# for p in _allPropertiesOf(inst, B):
127# p._update_from(inst, other)
128# u -= len(d)
129# return u # number of updates
132def _update_attrs(inst, *attrs):
133 '''(INTERNAL) Zap all named C{attrs} of an instance.
135 @return: The number of updates (C{int}), if any.
136 '''
137 try:
138 d = inst.__dict__
139 except AttributeError:
140 return 0
141 u = len(d)
142 if u: # zap attrs from inst.__dict__
143 _p = d.pop
144 for a in attrs:
145 _ = _p(a, MISSING)
146# if _ is MISSING and not hasattr(inst, a):
147# n = _MODS.named.classname(inst, prefixed=True)
148# a = _DOT_(n, _SPACE_(a, _invalid_))
149# raise _AssertionError(a, txt=repr(inst))
150# _ = _p(a, None) # redo: hasattr side effect
151 u -= len(d)
152 # assert u >= 0
153 return u # number of named C{attrs} zapped
156class _PropertyBase(property):
157 '''(INTERNAL) Base class for C{P/property/_RO}.
158 '''
159 def __init__(self, method, fget, fset, doc=NN):
161 if not callable(method):
162 self.getter(method) # PYCHOK no cover
164 self.method = method
165 self.name = method.__name__
166 d = doc or method.__doc__
167 if _FOR_DOCS and d:
168 self.__doc__ = d # PYCHOK no cover
170 property.__init__(self, fget, fset, self._fdel, d or _N_A_)
172 def _fdel(self, inst):
173 '''Zap the I{cached/memoized} C{property} value.
174 '''
175 self._update(inst, None) # PYCHOK no cover
177 def _fget(self, inst):
178 '''Get and I{cache/memoize} the C{property} value.
179 '''
180 try: # to get the value cached in instance' __dict__
181 return inst.__dict__[self.name]
182 except KeyError:
183 # cache the value in the instance' __dict__
184 inst.__dict__[self.name] = val = self.method(inst)
185 return val
187 def _fset_error(self, inst, val):
188 '''Throws an C{AttributeError}, always.
189 '''
190 n = _MODS.named.classname(inst)
191 n = _DOT_(n, self.name)
192 n = _EQUALSPACED_(n, repr(val))
193 raise self._Error(_immutable_, n, None)
195 def _update(self, inst, *unused):
196 '''(INTERNAL) Zap the I{cached/memoized} C{inst.__dict__[name]} item.
197 '''
198 inst.__dict__.pop(self.name, None) # name, NOT _name
200 def _update_from(self, inst, other):
201 '''(INTERNAL) Copy a I{cached/memoized} C{inst.__dict__[name]} item
202 from C{other.__dict__[name]} if present, otherwise zap it.
203 '''
204 n = self.name # name, NOT _name
205 v = other.__dict__.get(n, MISSING)
206 if v is MISSING:
207 inst.__dict__.pop(n, None)
208 else:
209 inst.__dict__[n] = v
211 def deleter(self, fdel):
212 '''Throws an C{AttributeError}, always.
213 '''
214 raise self._Error(_invalid_, self.deleter, fdel)
216 def getter(self, fget):
217 '''Throws an C{AttributeError}, always.
218 '''
219 raise self._Error(_invalid_, self.getter, fget)
221 def setter(self, fset):
222 '''Throws an C{AttributeError}, always.
223 '''
224 raise self._Error(_immutable_, self.setter, fset)
226 def _Error(self, kind, nameter, farg):
227 '''(INTERNAL) Return an C{AttributeError} instance.
228 '''
229 if farg:
230 n = _DOT_(self.name, nameter.__name__)
231 n = _SPACE_(n, farg.__name__)
232 else:
233 n = nameter
234 e = _SPACE_(kind, _MODS.named.classname(self))
235 return _AttributeError(e, txt=n)
238class Property_RO(_PropertyBase):
239 # No __doc__ on purpose
240 def __init__(self, method, doc=NN): # PYCHOK expected
241 '''New I{immutable}, I{caching}, I{memoizing} C{property} I{Factory}
242 to be used as C{decorator}.
244 @arg method: The callable being decorated as this C{property}'s C{getter},
245 to be invoked only once.
246 @kwarg doc: Optional property documentation (C{str}).
248 @note: Like standard Python C{property} without a C{setter}, but with
249 a more descriptive error message when set.
251 @see: Python 3's U{functools.cached_property<https://docs.Python.org/3/
252 library/functools.html#functools.cached_property>} and U{-.cache
253 <https://Docs.Python.org/3/library/functools.html#functools.cache>}
254 to I{cache} or I{memoize} the property value.
256 @see: Luciano Ramalho, "Fluent Python", page 636, O'Reilly, Example
257 19-24, 2016 p. 636 or Example 22-28, 2022 p. 869+ and U{class
258 Property<https://docs.Python.org/3/howto/descriptor.html>}.
259 '''
260 _fget = method if _FOR_DOCS else self._fget # XXX force method.__doc__ to epydoc
261 _PropertyBase.__init__(self, method, _fget, self._fset_error)
263 def __get__(self, inst, *unused): # PYCHOK 2 vs 3 args
264 if inst is None:
265 return self
266 try: # to get the cached value immediately
267 return inst.__dict__[self.name]
268 except (AttributeError, KeyError):
269 return self._fget(inst)
272class Property(Property_RO):
273 # No __doc__ on purpose
274 __init__ = Property_RO.__init__
275 '''New I{mutable}, I{caching}, I{memoizing} C{property} I{Factory}
276 to be used as C{decorator}.
278 @see: L{Property_RO} for more details.
280 @note: Unless and until the C{setter} is defined, this L{Property} behaves
281 like an I{immutable}, I{caching}, I{memoizing} L{Property_RO}.
282 '''
284 def setter(self, method):
285 '''Make this C{Property} I{mutable}.
287 @arg method: The callable being decorated as this C{Property}'s C{setter}.
289 @note: Setting a new property value always clears the previously I{cached}
290 or I{memoized} value I{after} invoking the B{C{method}}.
291 '''
292 if not callable(method):
293 _PropertyBase.setter(self, method) # PYCHOK no cover
295 if _FOR_DOCS: # XXX force method.__doc__ into epydoc
296 _PropertyBase.__init__(self, self.method, self.method, method)
297 else:
299 def _fset(inst, val):
300 '''Set and I{cache}, I{memoize} the C{property} value.
301 '''
302 method(inst, val)
303 self._update(inst) # un-cache this item
305 # class Property <https://docs.Python.org/3/howto/descriptor.html>
306 _PropertyBase.__init__(self, self.method, self._fget, _fset)
307 return self
310class property_RO(_PropertyBase):
311 # No __doc__ on purpose
312 _uname = NN
314 def __init__(self, method, doc=NN): # PYCHOK expected
315 '''New I{immutable}, standard C{property} to be used as C{decorator}.
317 @arg method: The callable being decorated as C{property}'s C{getter}.
318 @kwarg doc: Optional property documentation (C{str}).
320 @note: Like standard Python C{property} without a setter, but with
321 a more descriptive error message when set.
323 @see: L{Property_RO}.
324 '''
325 _PropertyBase.__init__(self, method, method, self._fset_error, doc=doc)
326 self._uname = NN(_UNDER_, self.name) # actual attr UNDER<name>
328 def _update(self, inst, *Clas): # PYCHOK signature
329 '''(INTERNAL) Zap the I{cached} C{B{inst}.__dict__[_name]} item.
330 '''
331 uname = self._uname
332 if uname in inst.__dict__:
333 if Clas: # overrides inst.__class__
334 d = Clas[0].__dict__.get(uname, MISSING)
335 else:
336 d = getattr(inst.__class__, uname, MISSING)
337# if d is MISSING: # XXX superfluous
338# for c in inst.__class__.__mro__[:-1]:
339# if uname in c.__dict__:
340# d = c.__dict__[uname]
341# break
342 if d is None: # remove inst value
343 inst.__dict__.pop(uname)
346class _NamedProperty(property):
347 '''Class C{property} with retrievable name.
348 '''
349 @Property_RO
350 def name(self):
351 '''Get the name of this C{property} (C{str}).
352 '''
353 return self.fget.__name__
356def property_doc_(doc):
357 '''Decorator for a standard C{property} with basic documentation.
359 @arg doc: The property documentation (C{str}).
361 @example:
363 >>> @property_doc_("documentation text.")
364 >>> def name(self):
365 >>> ...
366 >>>
367 >>> @name.setter
368 >>> def name(self, value):
369 >>> ...
370 '''
371 # See Luciano Ramalho, "Fluent Python", O'Reilly, Example 7-23,
372 # 2016 p. 212+, 2022 p. 331+, Example 9-22 and <https://
373 # Python-3-Patterns-Idioms-Test.ReadTheDocs.io/en/latest/PythonDecorators.html>
375 def _documented_property(method):
376 '''(INTERNAL) Return the documented C{property}.
377 '''
378 t = _get_and_set_ if doc.startswith(_SPACE_) else NN
379 return _NamedProperty(method, None, None, NN('Property to ', t, doc))
381 return _documented_property
384def _deprecated(call, kind, qual_d):
385 '''(INTERNAL) Decorator for DEPRECATED functions, methods, etc.
387 @see: Brett Slatkin, "Effective Python", page 105, 2nd ed,
388 Addison-Wesley, 2019.
389 '''
390 doc = _docof(call)
392 @_wraps(call) # PYCHOK self?
393 def _deprecated_call(*args, **kwds):
394 if qual_d: # function
395 q = qual_d
396 elif args: # method
397 q = _qualified(args[0], call.__name__)
398 else: # PYCHOK no cover
399 q = call.__name__
400 _throwarning(kind, q, doc)
401 return call(*args, **kwds)
403 return _deprecated_call
406def deprecated_class(cls_or_class):
407 '''Use inside __new__ or __init__ of a DEPRECATED class.
409 @arg cls_or_class: The class (C{cls} or C{Class}).
411 @note: NOT a decorator!
412 '''
413 if _WARNINGS_X_DEV:
414 q = _DOT_(cls_or_class.__module__, cls_or_class.__name__)
415 _throwarning(_class_, q, cls_or_class.__doc__)
418def deprecated_function(call):
419 '''Decorator for a DEPRECATED function.
421 @arg call: The deprecated function (C{callable}).
423 @return: The B{C{call}} DEPRECATED.
424 '''
425 return _deprecated(call, _function_, _DOT_(
426 call.__module__, call.__name__)) if \
427 _WARNINGS_X_DEV else call
430def deprecated_method(call):
431 '''Decorator for a DEPRECATED method.
433 @arg call: The deprecated method (C{callable}).
435 @return: The B{C{call}} DEPRECATED.
436 '''
437 return _deprecated(call, _method_, NN) if _WARNINGS_X_DEV else call
440def _deprecated_module(name): # PYCHOK no cover
441 '''(INTERNAL) Callable within a DEPRECATED module.
442 '''
443 if _WARNINGS_X_DEV:
444 _throwarning(_module_, name, _dont_use_)
447if _WARNINGS_X_DEV:
448 class deprecated_property(_PropertyBase):
449 '''Decorator for a DEPRECATED C{property} or C{Property}.
450 '''
451 def __init__(self, method):
452 '''Decorator for a DEPRECATED C{property} or C{Property} getter.
453 '''
454 doc = _docof(method)
456 def _fget(inst): # PYCHOK no cover
457 '''Get the C{property} or C{Property} value.
458 '''
459 q = _qualified(inst, self.name)
460 _throwarning(property.__name__, q, doc)
461 return self.method(inst) # == method
463 _PropertyBase.__init__(self, method, _fget, None, doc=doc)
465 def setter(self, method):
466 '''Decorator for a DEPRECATED C{property} or C{Property} setter.
468 @arg method: The callable being decorated as this C{Property}'s C{setter}.
470 @note: Setting a new property value always clears the previously I{cached}
471 or I{memoized} value I{after} invoking the B{C{method}}.
472 '''
473 if not callable(method):
474 _PropertyBase.setter(self, method) # PYCHOK no cover
476 if _FOR_DOCS: # XXX force method.__doc__ into epydoc
477 _PropertyBase.__init__(self, self.method, self.method, method)
478 else:
480 def _fset(inst, val):
481 '''Set the C{property} or C{Property} value.
482 '''
483 q = _qualified(inst, self.name)
484 _throwarning(property.__name__, q, _docof(method))
485 method(inst, val)
486 # self._update(inst) # un-cache this item
488 # class Property <https://docs.Python.org/3/howto/descriptor.html>
489 _PropertyBase.__init__(self, self.method, self._fget, _fset)
490 return self
492else: # PYCHOK no cover
493 class deprecated_property(property): # PYCHOK expected
494 '''Decorator for a DEPRECATED C{property} or C{Property}.
495 '''
496 pass
498deprecated_Property = deprecated_property
501def deprecated_Property_RO(method):
502 '''Decorator for a DEPRECATED L{Property_RO}.
504 @arg method: The C{Property_RO.fget} method (C{callable}).
506 @return: The B{C{method}} DEPRECATED.
507 '''
508 return _deprecated_RO(method, Property_RO)
511def deprecated_property_RO(method):
512 '''Decorator for a DEPRECATED L{property_RO}.
514 @arg method: The C{property_RO.fget} method (C{callable}).
516 @return: The B{C{method}} DEPRECATED.
517 '''
518 return _deprecated_RO(method, property_RO)
521def _deprecated_RO(method, _RO):
522 '''(INTERNAL) Create a DEPRECATED C{property_RO} or C{Property_RO}.
523 '''
524 doc = _docof(method)
526 if _WARNINGS_X_DEV:
528 class _Deprecated_RO(_PropertyBase):
529 __doc__ = doc
531 def __init__(self, method):
532 _PropertyBase.__init__(self, method, self._fget, self._fset_error, doc=doc)
534 def _fget(self, inst): # PYCHOK no cover
535 q = _qualified(inst, self.name)
536 _throwarning(_RO.__name__, q, doc)
537 return self.method(inst)
539 return _Deprecated_RO(method)
540 else: # PYCHOK no cover
541 return _RO(method, doc=doc)
544def _docof(obj):
545 '''(INTERNAL) Get uniform DEPRECATED __doc__ string.
546 '''
547 try:
548 d = obj.__doc__.strip()
549 i = d.find(_DEPRECATED_)
550 except AttributeError:
551 i = -1
552 return _DOT_(_DEPRECATED_, NN) if i < 0 else d[i:]
555def _qualified(inst, name):
556 '''(INTERNAL) Fully qualify a name.
557 '''
558 # _DOT_(inst.classname, name), not _DOT_(inst.named4, name)
559 c = inst.__class__
560 q = _DOT_(c.__module__, c.__name__, name)
561 return q
564class DeprecationWarnings(object):
565 '''(INTERNAL) Handle C{DeprecationWaring}s.
566 '''
567 _Warnings = 0
569 def __call__(self): # for backward compatibility
570 '''Have any C{DeprecationWarning}s been reported or raised?
572 @return: The number of C{DeprecationWarning}s (C{int}) so
573 far or C{None} if not enabled.
575 @note: To get C{DeprecationWarning}s if any, run C{python}
576 with env var C{PYGEODESY_WARNINGS} set to a non-empty
577 string I{AND} use C{python[3]} command line option
578 C{-X dev}, C{-W always} or C{-W error}, etc.
579 '''
580 return self.Warnings
582 def throw(self, kind, name, doc, **stacklevel): # stacklevel=3
583 '''Report or raise a C{DeprecationWarning}.
584 '''
585 line = doc.split(_DNL_, 1)[0].strip()
586 name = _MODS.streprs.Fmt.CURLY(L=name)
587 text = _SPACE_(kind, name, _has_been_, *line.split())
588 kwds = _xkwds(stacklevel, stacklevel=3)
589 # XXX invoke warn or raise DeprecationWarning(text)
590 self._warn(text, category=DeprecationWarning, **kwds)
591 self._Warnings += 1
593 @Property_RO
594 def _warn(self):
595 '''Get Python's C{warnings.warn}.
596 '''
597 from warnings import warn
598 return warn
600 @property_RO
601 def Warnings(self):
602 '''Get the number of C{DeprecationWarning}s (C{int}) so
603 far or C{None} if not enabled.
604 '''
605 return self._Warnings if _WARNINGS_X_DEV else None
607DeprecationWarnings = DeprecationWarnings() # PYCHOK singleton
608_throwarning = DeprecationWarnings.throw
610# **) MIT License
611#
612# Copyright (C) 2016-2024 -- mrJean1 at Gmail -- All Rights Reserved.
613#
614# Permission is hereby granted, free of charge, to any person obtaining a
615# copy of this software and associated documentation files (the "Software"),
616# to deal in the Software without restriction, including without limitation
617# the rights to use, copy, modify, merge, publish, distribute, sublicense,
618# and/or sell copies of the Software, and to permit persons to whom the
619# Software is furnished to do so, subject to the following conditions:
620#
621# The above copyright notice and this permission notice shall be included
622# in all copies or substantial portions of the Software.
623#
624# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
625# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
626# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
627# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
628# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
629# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
630# OTHER DEALINGS IN THE SOFTWARE.