{{ message }}
forked from python/cpython
-
Notifications
You must be signed in to change notification settings - Fork 2
Expand file tree
/
Copy pathenum.py
More file actions
1053 lines (935 loc) · 38.9 KB
/
Copy pathenum.py
File metadata and controls
1053 lines (935 loc) · 38.9 KB
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
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
import sys
from types import MappingProxyType, DynamicClassAttribute
__all__ = [
'EnumMeta',
'Enum', 'IntEnum', 'Flag', 'IntFlag',
'auto', 'unique',
]
def _is_descriptor(obj):
"""
Returns True if obj is a descriptor, False otherwise.
"""
return (
hasattr(obj, '__get__') or
hasattr(obj, '__set__') or
hasattr(obj, '__delete__')
)
def _is_dunder(name):
"""
Returns True if a __dunder__ name, False otherwise.
"""
return (
len(name) > 4 and
name[:2] == name[-2:] == '__' and
name[2] != '_' and
name[-3] != '_'
)
def _is_sunder(name):
"""
Returns True if a _sunder_ name, False otherwise.
"""
return (
len(name) > 2 and
name[0] == name[-1] == '_' and
name[1:2] != '_' and
name[-2:-1] != '_'
)
def _is_private(cls_name, name):
# do not use `re` as `re` imports `enum`
pattern = '_%s__' % (cls_name, )
pat_len = len(pattern)
if (
len(name) > pat_len
and name.startswith(pattern)
and name[pat_len:pat_len+1] != ['_']
and (name[-1] != '_' or name[-2] != '_')
):
return True
else:
return False
def _make_class_unpicklable(cls):
"""
Make the given class un-picklable.
"""
def _break_on_call_reduce(self, proto):
raise TypeError('%r cannot be pickled' % self)
cls.__reduce_ex__ = _break_on_call_reduce
cls.__module__ = '<unknown>'
_auto_null = object()
class auto:
"""
Instances are replaced with an appropriate value in Enum class suites.
"""
value = _auto_null
class _EnumDict(dict):
"""
Track enum member order and ensure member names are not reused.
EnumMeta will use the names found in self._member_names as the
enumeration member names.
"""
def __init__(self):
super().__init__()
self._member_names = []
self._last_values = []
self._ignore = []
self._auto_called = False
def __setitem__(self, key, value):
"""
Changes anything not dundered or not a descriptor.
If an enum member name is used twice, an error is raised; duplicate
values are not checked for.
Single underscore (sunder) names are reserved.
"""
if _is_private(self._cls_name, key):
import warnings
warnings.warn(
"private variables, such as %r, will be normal attributes in 3.11"
% (key, ),
DeprecationWarning,
stacklevel=2,
)
if _is_sunder(key):
if key not in (
'_order_', '_create_pseudo_member_',
'_generate_next_value_', '_missing_', '_ignore_',
):
raise ValueError('_names_ are reserved for future Enum use')
if key == '_generate_next_value_':
# check if members already defined as auto()
if self._auto_called:
raise TypeError("_generate_next_value_ must be defined before members")
setattr(self, '_generate_next_value', value)
elif key == '_ignore_':
if isinstance(value, str):
value = value.replace(',',' ').split()
else:
value = list(value)
self._ignore = value
already = set(value) & set(self._member_names)
if already:
raise ValueError(
'_ignore_ cannot specify already set names: %r'
% (already, )
)
elif _is_dunder(key):
if key == '__order__':
key = '_order_'
elif key in self._member_names:
# descriptor overwriting an enum?
raise TypeError('Attempted to reuse key: %r' % key)
elif key in self._ignore:
pass
elif not _is_descriptor(value):
if key in self:
# enum overwriting a descriptor?
raise TypeError('%r already defined as: %r' % (key, self[key]))
if isinstance(value, auto):
if value.value == _auto_null:
value.value = self._generate_next_value(
key,
1,
len(self._member_names),
self._last_values[:],
)
self._auto_called = True
value = value.value
self._member_names.append(key)
self._last_values.append(value)
super().__setitem__(key, value)
# Dummy value for Enum as EnumMeta explicitly checks for it, but of course
# until EnumMeta finishes running the first time the Enum class doesn't exist.
# This is also why there are checks in EnumMeta like `if Enum is not None`
Enum = None
class EnumMeta(type):
"""
Metaclass for Enum
"""
@classmethod
def __prepare__(metacls, cls, bases, **kwds):
# check that previous enum members do not exist
metacls._check_for_existing_members(cls, bases)
# create the namespace dict
enum_dict = _EnumDict()
enum_dict._cls_name = cls
# inherit previous flags and _generate_next_value_ function
member_type, first_enum = metacls._get_mixins_(cls, bases)
if first_enum is not None:
enum_dict['_generate_next_value_'] = getattr(
first_enum, '_generate_next_value_', None,
)
return enum_dict
def __new__(metacls, cls, bases, classdict, **kwds):
# an Enum class is final once enumeration items have been defined; it
# cannot be mixed with other types (int, float, etc.) if it has an
# inherited __new__ unless a new __new__ is defined (or the resulting
# class will fail).
#
# remove any keys listed in _ignore_
classdict.setdefault('_ignore_', []).append('_ignore_')
ignore = classdict['_ignore_']
for key in ignore:
classdict.pop(key, None)
member_type, first_enum = metacls._get_mixins_(cls, bases)
__new__, save_new, use_args = metacls._find_new_(
classdict, member_type, first_enum,
)
# save enum items into separate mapping so they don't get baked into
# the new class
enum_members = {k: classdict[k] for k in classdict._member_names}
for name in classdict._member_names:
del classdict[name]
# adjust the sunders
_order_ = classdict.pop('_order_', None)
# check for illegal enum names (any others?)
invalid_names = set(enum_members) & {'mro', ''}
if invalid_names:
raise ValueError('Invalid enum member name: {0}'.format(
','.join(invalid_names)))
# create a default docstring if one has not been provided
if '__doc__' not in classdict:
classdict['__doc__'] = 'An enumeration.'
enum_class = super().__new__(metacls, cls, bases, classdict, **kwds)
enum_class._member_names_ = [] # names in definition order
enum_class._member_map_ = {} # name->value map
enum_class._member_type_ = member_type
# save DynamicClassAttribute attributes from super classes so we know
# if we can take the shortcut of storing members in the class dict
dynamic_attributes = {
k for c in enum_class.mro()
for k, v in c.__dict__.items()
if isinstance(v, DynamicClassAttribute)
}
# Reverse value->name map for hashable values.
enum_class._value2member_map_ = {}
# If a custom type is mixed into the Enum, and it does not know how
# to pickle itself, pickle.dumps will succeed but pickle.loads will
# fail. Rather than have the error show up later and possibly far
# from the source, sabotage the pickle protocol for this class so
# that pickle.dumps also fails.
#
# However, if the new class implements its own __reduce_ex__, do not
# sabotage -- it's on them to make sure it works correctly. We use
# __reduce_ex__ instead of any of the others as it is preferred by
# pickle over __reduce__, and it handles all pickle protocols.
if '__reduce_ex__' not in classdict:
if member_type is not object:
methods = ('__getnewargs_ex__', '__getnewargs__',
'__reduce_ex__', '__reduce__')
if not any(m in member_type.__dict__ for m in methods):
if '__new__' in classdict:
# too late, sabotage
_make_class_unpicklable(enum_class)
else:
# final attempt to verify that pickling would work:
# travel mro until __new__ is found, checking for
# __reduce__ and friends along the way -- if any of them
# are found before/when __new__ is found, pickling should
# work
sabotage = None
for chain in bases:
for base in chain.__mro__:
if base is object:
continue
elif any(m in base.__dict__ for m in methods):
# found one, we're good
sabotage = False
break
elif '__new__' in base.__dict__:
# not good
sabotage = True
break
if sabotage is not None:
break
if sabotage:
_make_class_unpicklable(enum_class)
# instantiate them, checking for duplicates as we go
# we instantiate first instead of checking for duplicates first in case
# a custom __new__ is doing something funky with the values -- such as
# auto-numbering ;)
for member_name in classdict._member_names:
value = enum_members[member_name]
if not isinstance(value, tuple):
args = (value, )
else:
args = value
if member_type is tuple: # special case for tuple enums
args = (args, ) # wrap it one more time
if not use_args:
enum_member = __new__(enum_class)
if not hasattr(enum_member, '_value_'):
enum_member._value_ = value
else:
enum_member = __new__(enum_class, *args)
if not hasattr(enum_member, '_value_'):
if member_type is object:
enum_member._value_ = value
else:
enum_member._value_ = member_type(*args)
value = enum_member._value_
enum_member._name_ = member_name
enum_member.__objclass__ = enum_class
enum_member.__init__(*args)
# If another member with the same value was already defined, the
# new member becomes an alias to the existing one.
for name, canonical_member in enum_class._member_map_.items():
if canonical_member._value_ == enum_member._value_:
enum_member = canonical_member
break
else:
# Aliases don't appear in member names (only in __members__).
enum_class._member_names_.append(member_name)
# performance boost for any member that would not shadow
# a DynamicClassAttribute
if member_name not in dynamic_attributes:
setattr(enum_class, member_name, enum_member)
# now add to _member_map_
enum_class._member_map_[member_name] = enum_member
try:
# This may fail if value is not hashable. We can't add the value
# to the map, and by-value lookups for this value will be
# linear.
enum_class._value2member_map_[value] = enum_member
except TypeError:
pass
# double check that repr and friends are not the mixin's or various
# things break (such as pickle)
# however, if the method is defined in the Enum itself, don't replace
# it
for name in ('__repr__', '__str__', '__format__', '__reduce_ex__'):
if name in classdict:
continue
class_method = getattr(enum_class, name)
obj_method = getattr(member_type, name, None)
enum_method = getattr(first_enum, name, None)
if obj_method is not None and obj_method is class_method:
setattr(enum_class, name, enum_method)
# replace any other __new__ with our own (as long as Enum is not None,
# anyway) -- again, this is to support pickle
if Enum is not None:
# if the user defined their own __new__, save it before it gets
# clobbered in case they subclass later
if save_new:
enum_class.__new_member__ = __new__
enum_class.__new__ = Enum.__new__
# py3 support for definition order (helps keep py2/py3 code in sync)
if _order_ is not None:
if isinstance(_order_, str):
_order_ = _order_.replace(',', ' ').split()
if _order_ != enum_class._member_names_:
raise TypeError('member order does not match _order_')
return enum_class
def __bool__(self):
"""
classes/types should always be True.
"""
return True
def __call__(cls, value, names=None, *, module=None, qualname=None, type=None, start=1):
"""
Either returns an existing member, or creates a new enum class.
This method is used both when an enum class is given a value to match
to an enumeration member (i.e. Color(3)) and for the functional API
(i.e. Color = Enum('Color', names='RED GREEN BLUE')).
When used for the functional API:
`value` will be the name of the new class.
`names` should be either a string of white-space/comma delimited names
(values will start at `start`), or an iterator/mapping of name, value pairs.
`module` should be set to the module this class is being created in;
if it is not set, an attempt to find that module will be made, but if
it fails the class will not be picklable.
`qualname` should be set to the actual location this class can be found
at in its module; by default it is set to the global scope. If this is
not correct, unpickling will fail in some circumstances.
`type`, if set, will be mixed in as the first base class.
"""
if names is None: # simple value lookup
return cls.__new__(cls, value)
# otherwise, functional API: we're creating a new Enum type
return cls._create_(
value,
names,
module=module,
qualname=qualname,
type=type,
start=start,
)
def __contains__(cls, obj):
if not isinstance(obj, Enum):
import warnings
warnings.warn(
"in 3.12 __contains__ will no longer raise TypeError, but will return True if\n"
"obj is a member or a member's value",
DeprecationWarning,
stacklevel=2,
)
raise TypeError(
"unsupported operand type(s) for 'in': '%s' and '%s'" % (
type(obj).__qualname__, cls.__class__.__qualname__))
return isinstance(obj, cls) and obj._name_ in cls._member_map_
def __delattr__(cls, attr):
# nicer error message when someone tries to delete an attribute
# (see issue19025).
if attr in cls._member_map_:
raise AttributeError("%s: cannot delete Enum member." % cls.__name__)
super().__delattr__(attr)
def __dir__(self):
return (
['__class__', '__doc__', '__members__', '__module__']
+ self._member_names_
)
def __getattr__(cls, name):
"""
Return the enum member matching `name`
We use __getattr__ instead of descriptors or inserting into the enum
class' __dict__ in order to support `name` and `value` being both
properties for enum members (which live in the class' __dict__) and
enum members themselves.
"""
if _is_dunder(name):
raise AttributeError(name)
try:
return cls._member_map_[name]
except KeyError:
raise AttributeError(name) from None
def __getitem__(cls, name):
return cls._member_map_[name]
def __iter__(cls):
"""
Returns members in definition order.
"""
return (cls._member_map_[name] for name in cls._member_names_)
def __len__(cls):
return len(cls._member_names_)
@property
def __members__(cls):
"""
Returns a mapping of member name->value.
This mapping lists all enum members, including aliases. Note that this
is a read-only view of the internal mapping.
"""
return MappingProxyType(cls._member_map_)
def __repr__(cls):
return "<enum %r>" % cls.__name__
def __reversed__(cls):
"""
Returns members in reverse definition order.
"""
return (cls._member_map_[name] for name in reversed(cls._member_names_))
def __setattr__(cls, name, value):
"""
Block attempts to reassign Enum members.
A simple assignment to the class namespace only changes one of the
several possible ways to get an Enum member from the Enum class,
resulting in an inconsistent Enumeration.
"""
member_map = cls.__dict__.get('_member_map_', {})
if name in member_map:
raise AttributeError('Cannot reassign members.')
super().__setattr__(name, value)
def _create_(cls, class_name, names, *, module=None, qualname=None, type=None, start=1):
"""
Convenience method to create a new Enum class.
`names` can be:
* A string containing member names, separated either with spaces or
commas. Values are incremented by 1 from `start`.
* An iterable of member names. Values are incremented by 1 from `start`.
* An iterable of (member name, value) pairs.
* A mapping of member name -> value pairs.
"""
metacls = cls.__class__
bases = (cls, ) if type is None else (type, cls)
_, first_enum = cls._get_mixins_(cls, bases)
classdict = metacls.__prepare__(class_name, bases)
# special processing needed for names?
if isinstance(names, str):
names = names.replace(',', ' ').split()
if isinstance(names, (tuple, list)) and names and isinstance(names[0], str):
original_names, names = names, []
last_values = []
for count, name in enumerate(original_names):
value = first_enum._generate_next_value_(name, start, count, last_values[:])
last_values.append(value)
names.append((name, value))
# Here, names is either an iterable of (name, value) or a mapping.
for item in names:
if isinstance(item, str):
member_name, member_value = item, names[item]
else:
member_name, member_value = item
classdict[member_name] = member_value
enum_class = metacls.__new__(metacls, class_name, bases, classdict)
# TODO: replace the frame hack if a blessed way to know the calling
# module is ever developed
if module is None:
try:
module = sys._getframe(2).f_globals['__name__']
except (AttributeError, ValueError, KeyError):
pass
if module is None:
_make_class_unpicklable(enum_class)
else:
enum_class.__module__ = module
if qualname is not None:
enum_class.__qualname__ = qualname
return enum_class
def _convert_(cls, name, module, filter, source=None):
"""
Create a new Enum subclass that replaces a collection of global constants
"""
# convert all constants from source (or module) that pass filter() to
# a new Enum called name, and export the enum and its members back to
# module;
# also, replace the __reduce_ex__ method so unpickling works in
# previous Python versions
module_globals = vars(sys.modules[module])
if source:
source = vars(source)
else:
source = module_globals
# _value2member_map_ is populated in the same order every time
# for a consistent reverse mapping of number to name when there
# are multiple names for the same number.
members = [
(name, value)
for name, value in source.items()
if filter(name)]
try:
# sort by value
members.sort(key=lambda t: (t[1], t[0]))
except TypeError:
# unless some values aren't comparable, in which case sort by name
members.sort(key=lambda t: t[0])
cls = cls(name, members, module=module)
cls.__reduce_ex__ = _reduce_ex_by_name
module_globals.update(cls.__members__)
module_globals[name] = cls
return cls
@staticmethod
def _check_for_existing_members(class_name, bases):
for chain in bases:
for base in chain.__mro__:
if issubclass(base, Enum) and base._member_names_:
raise TypeError(
"%s: cannot extend enumeration %r"
% (class_name, base.__name__)
)
@staticmethod
def _get_mixins_(class_name, bases):
"""
Returns the type for creating enum members, and the first inherited
enum class.
bases: the tuple of bases that was given to __new__
"""
if not bases:
return object, Enum
def _find_data_type(bases):
data_types = set()
for chain in bases:
candidate = None
for base in chain.__mro__:
if base is object:
continue
elif issubclass(base, Enum):
if base._member_type_ is not object:
data_types.add(base._member_type_)
break
elif '__new__' in base.__dict__:
if issubclass(base, Enum):
continue
data_types.add(candidate or base)
break
else:
candidate = candidate or base
if len(data_types) > 1:
raise TypeError('%r: too many data types: %r' % (class_name, data_types))
elif data_types:
return data_types.pop()
else:
return None
# ensure final parent class is an Enum derivative, find any concrete
# data type, and check that Enum has no members
first_enum = bases[-1]
if not issubclass(first_enum, Enum):
raise TypeError("new enumerations should be created as "
"`EnumName([mixin_type, ...] [data_type,] enum_type)`")
member_type = _find_data_type(bases) or object
if first_enum._member_names_:
raise TypeError("Cannot extend enumerations")
return member_type, first_enum
@staticmethod
def _find_new_(classdict, member_type, first_enum):
"""
Returns the __new__ to be used for creating the enum members.
classdict: the class dictionary given to __new__
member_type: the data type whose __new__ will be used by default
first_enum: enumeration to check for an overriding __new__
"""
# now find the correct __new__, checking to see of one was defined
# by the user; also check earlier enum classes in case a __new__ was
# saved as __new_member__
__new__ = classdict.get('__new__', None)
# should __new__ be saved as __new_member__ later?
save_new = __new__ is not None
if __new__ is None:
# check all possibles for __new_member__ before falling back to
# __new__
for method in ('__new_member__', '__new__'):
for possible in (member_type, first_enum):
target = getattr(possible, method, None)
if target not in {
None,
None.__new__,
object.__new__,
Enum.__new__,
}:
__new__ = target
break
if __new__ is not None:
break
else:
__new__ = object.__new__
# if a non-object.__new__ is used then whatever value/tuple was
# assigned to the enum member name will be passed to __new__ and to the
# new enum member's __init__
if __new__ is object.__new__:
use_args = False
else:
use_args = True
return __new__, save_new, use_args
class Enum(metaclass=EnumMeta):
"""
Generic enumeration.
Derive from this class to define new enumerations.
"""
def __new__(cls, value):
# all enum instances are actually created during class construction
# without calling this method; this method is called by the metaclass'
# __call__ (i.e. Color(3) ), and by pickle
if type(value) is cls:
# For lookups like Color(Color.RED)
return value
# by-value search for a matching enum member
# see if it's in the reverse mapping (for hashable values)
try:
return cls._value2member_map_[value]
except KeyError:
# Not found, no need to do long O(n) search
pass
except TypeError:
# not there, now do long search -- O(n) behavior
for member in cls._member_map_.values():
if member._value_ == value:
return member
# still not found -- try _missing_ hook
try:
exc = None
result = cls._missing_(value)
except Exception as e:
exc = e
result = None
try:
if isinstance(result, cls):
return result
else:
ve_exc = ValueError("%r is not a valid %s" % (value, cls.__qualname__))
if result is None and exc is None:
raise ve_exc
elif exc is None:
exc = TypeError(
'error in %s._missing_: returned %r instead of None or a valid member'
% (cls.__name__, result)
)
if not isinstance(exc, ValueError):
exc.__context__ = ve_exc
raise exc
finally:
# ensure all variables that could hold an exception are destroyed
exc = None
ve_exc = None
def _generate_next_value_(name, start, count, last_values):
"""
Generate the next value when not given.
name: the name of the member
start: the initial start value or None
count: the number of existing members
last_value: the last value assigned or None
"""
for last_value in reversed(last_values):
try:
return last_value + 1
except TypeError:
pass
else:
return start
@classmethod
def _missing_(cls, value):
return None
def __repr__(self):
return "<%s.%s: %r>" % (
self.__class__.__name__, self._name_, self._value_)
def __str__(self):
return "%s.%s" % (self.__class__.__name__, self._name_)
def __dir__(self):
"""
Returns all members and all public methods
"""
added_behavior = [
m
for cls in self.__class__.mro()
for m in cls.__dict__
if m[0] != '_' and m not in self._member_map_
] + [m for m in self.__dict__ if m[0] != '_']
return (['__class__', '__doc__', '__module__'] + added_behavior)
def __format__(self, format_spec):
"""
Returns format using actual value type unless __str__ has been overridden.
"""
# mixed-in Enums should use the mixed-in type's __format__, otherwise
# we can get strange results with the Enum name showing up instead of
# the value
# pure Enum branch, or branch with __str__ explicitly overridden
str_overridden = type(self).__str__ not in (Enum.__str__, Flag.__str__)
if self._member_type_ is object or str_overridden:
cls = str
val = str(self)
# mix-in branch
else:
cls = self._member_type_
val = self._value_
return cls.__format__(val, format_spec)
def __hash__(self):
return hash(self._name_)
def __reduce_ex__(self, proto):
return self.__class__, (self._value_, )
# DynamicClassAttribute is used to provide access to the `name` and
# `value` properties of enum members while keeping some measure of
# protection from modification, while still allowing for an enumeration
# to have members named `name` and `value`. This works because enumeration
# members are not set directly on the enum class -- __getattr__ is
# used to look them up.
@DynamicClassAttribute
def name(self):
"""The name of the Enum member."""
return self._name_
@DynamicClassAttribute
def value(self):
"""The value of the Enum member."""
return self._value_
class IntEnum(int, Enum):
"""Enum where members are also (and must be) ints"""
def _reduce_ex_by_name(self, proto):
return self.name
class Flag(Enum):
"""
Support for flags
"""
def _generate_next_value_(name, start, count, last_values):
"""
Generate the next value when not given.
name: the name of the member
start: the initial start value or None
count: the number of existing members
last_value: the last value assigned or None
"""
if not count:
return start if start is not None else 1
for last_value in reversed(last_values):
try:
high_bit = _high_bit(last_value)
break
except Exception:
raise TypeError('Invalid Flag value: %r' % last_value) from None
return 2 ** (high_bit+1)
@classmethod
def _missing_(cls, value):
"""
Returns member (possibly creating it) if one can be found for value.
"""
original_value = value
if value < 0:
value = ~value
possible_member = cls._create_pseudo_member_(value)
if original_value < 0:
possible_member = ~possible_member
return possible_member
@classmethod
def _create_pseudo_member_(cls, value):
"""
Create a composite member iff value contains only members.
"""
pseudo_member = cls._value2member_map_.get(value, None)
if pseudo_member is None:
# verify all bits are accounted for
_, extra_flags = _decompose(cls, value)
if extra_flags:
raise ValueError("%r is not a valid %s" % (value, cls.__qualname__))
# construct a singleton enum pseudo-member
pseudo_member = object.__new__(cls)
pseudo_member._name_ = None
pseudo_member._value_ = value
# use setdefault in case another thread already created a composite
# with this value
pseudo_member = cls._value2member_map_.setdefault(value, pseudo_member)
return pseudo_member
def __contains__(self, other):
"""
Returns True if self has at least the same flags set as other.
"""
if not isinstance(other, self.__class__):
raise TypeError(
"unsupported operand type(s) for 'in': '%s' and '%s'" % (
type(other).__qualname__, self.__class__.__qualname__))
return other._value_ & self._value_ == other._value_
def __repr__(self):
cls = self.__class__
if self._name_ is not None:
return '<%s.%s: %r>' % (cls.__name__, self._name_, self._value_)
members, uncovered = _decompose(cls, self._value_)
return '<%s.%s: %r>' % (
cls.__name__,
'|'.join([str(m._name_ or m._value_) for m in members]),
self._value_,
)
def __str__(self):
cls = self.__class__
if self._name_ is not None:
return '%s.%s' % (cls.__name__, self._name_)
members, uncovered = _decompose(cls, self._value_)
if len(members) == 1 and members[0]._name_ is None:
return '%s.%r' % (cls.__name__, members[0]._value_)
else:
return '%s.%s' % (
cls.__name__,
'|'.join([str(m._name_ or m._value_) for m in members]),
)
def __bool__(self):
return bool(self._value_)
def __or__(self, other):
if not isinstance(other, self.__class__):
return NotImplemented
return self.__class__(self._value_ | other._value_)
def __and__(self, other):
if not isinstance(other, self.__class__):
return NotImplemented
return self.__class__(self._value_ & other._value_)
def __xor__(self, other):
if not isinstance(other, self.__class__):
return NotImplemented
return self.__class__(self._value_ ^ other._value_)
def __invert__(self):
members, uncovered = _decompose(self.__class__, self._value_)
inverted = self.__class__(0)
for m in self.__class__:
if m not in members and not (m._value_ & self._value_):
inverted = inverted | m
return self.__class__(inverted)
class IntFlag(int, Flag):
"""
Support for integer-based Flags
"""
@classmethod
def _missing_(cls, value):
"""
Returns member (possibly creating it) if one can be found for value.
"""
if not isinstance(value, int):
raise ValueError("%r is not a valid %s" % (value, cls.__qualname__))
new_member = cls._create_pseudo_member_(value)
return new_member
@classmethod
def _create_pseudo_member_(cls, value):
"""
Create a composite member iff value contains only members.
"""
pseudo_member = cls._value2member_map_.get(value, None)
if pseudo_member is None:
need_to_create = [value]
# get unaccounted for bits
_, extra_flags = _decompose(cls, value)
# timer = 10
while extra_flags:
# timer -= 1
bit = _high_bit(extra_flags)
flag_value = 2 ** bit
if (flag_value not in cls._value2member_map_ and
flag_value not in need_to_create
):
need_to_create.append(flag_value)
if extra_flags == -flag_value:
extra_flags = 0
else:
extra_flags ^= flag_value
for value in reversed(need_to_create):
# construct singleton pseudo-members
pseudo_member = int.__new__(cls, value)
pseudo_member._name_ = None
pseudo_member._value_ = value
# use setdefault in case another thread already created a composite
# with this value
pseudo_member = cls._value2member_map_.setdefault(value, pseudo_member)
return pseudo_member
def __or__(self, other):
if not isinstance(other, (self.__class__, int)):
return NotImplemented
result = self.__class__(self._value_ | self.__class__(other)._value_)
return result
def __and__(self, other):
if not isinstance(other, (self.__class__, int)):
return NotImplemented
return self.__class__(self._value_ & self.__class__(other)._value_)
def __xor__(self, other):
if not isinstance(other, (self.__class__, int)):
return NotImplemented
return self.__class__(self._value_ ^ self.__class__(other)._value_)
__ror__ = __or__
__rand__ = __and__
__rxor__ = __xor__
def __invert__(self):
You can’t perform that action at this time.