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| 1 """Python Enumerations""" |
| 2 |
| 3 import sys as _sys |
| 4 |
| 5 __all__ = ['Enum', 'IntEnum', 'unique'] |
| 6 |
| 7 version = 1, 1, 6 |
| 8 |
| 9 pyver = float('%s.%s' % _sys.version_info[:2]) |
| 10 |
| 11 try: |
| 12 any |
| 13 except NameError: |
| 14 def any(iterable): |
| 15 for element in iterable: |
| 16 if element: |
| 17 return True |
| 18 return False |
| 19 |
| 20 try: |
| 21 from collections import OrderedDict |
| 22 except ImportError: |
| 23 OrderedDict = None |
| 24 |
| 25 try: |
| 26 basestring |
| 27 except NameError: |
| 28 # In Python 2 basestring is the ancestor of both str and unicode |
| 29 # in Python 3 it's just str, but was missing in 3.1 |
| 30 basestring = str |
| 31 |
| 32 try: |
| 33 unicode |
| 34 except NameError: |
| 35 # In Python 3 unicode no longer exists (it's just str) |
| 36 unicode = str |
| 37 |
| 38 class _RouteClassAttributeToGetattr(object): |
| 39 """Route attribute access on a class to __getattr__. |
| 40 |
| 41 This is a descriptor, used to define attributes that act differently when |
| 42 accessed through an instance and through a class. Instance access remains |
| 43 normal, but access to an attribute through a class will be routed to the |
| 44 class's __getattr__ method; this is done by raising AttributeError. |
| 45 |
| 46 """ |
| 47 def __init__(self, fget=None): |
| 48 self.fget = fget |
| 49 |
| 50 def __get__(self, instance, ownerclass=None): |
| 51 if instance is None: |
| 52 raise AttributeError() |
| 53 return self.fget(instance) |
| 54 |
| 55 def __set__(self, instance, value): |
| 56 raise AttributeError("can't set attribute") |
| 57 |
| 58 def __delete__(self, instance): |
| 59 raise AttributeError("can't delete attribute") |
| 60 |
| 61 |
| 62 def _is_descriptor(obj): |
| 63 """Returns True if obj is a descriptor, False otherwise.""" |
| 64 return ( |
| 65 hasattr(obj, '__get__') or |
| 66 hasattr(obj, '__set__') or |
| 67 hasattr(obj, '__delete__')) |
| 68 |
| 69 |
| 70 def _is_dunder(name): |
| 71 """Returns True if a __dunder__ name, False otherwise.""" |
| 72 return (name[:2] == name[-2:] == '__' and |
| 73 name[2:3] != '_' and |
| 74 name[-3:-2] != '_' and |
| 75 len(name) > 4) |
| 76 |
| 77 |
| 78 def _is_sunder(name): |
| 79 """Returns True if a _sunder_ name, False otherwise.""" |
| 80 return (name[0] == name[-1] == '_' and |
| 81 name[1:2] != '_' and |
| 82 name[-2:-1] != '_' and |
| 83 len(name) > 2) |
| 84 |
| 85 |
| 86 def _make_class_unpicklable(cls): |
| 87 """Make the given class un-picklable.""" |
| 88 def _break_on_call_reduce(self, protocol=None): |
| 89 raise TypeError('%r cannot be pickled' % self) |
| 90 cls.__reduce_ex__ = _break_on_call_reduce |
| 91 cls.__module__ = '<unknown>' |
| 92 |
| 93 |
| 94 class _EnumDict(dict): |
| 95 """Track enum member order and ensure member names are not reused. |
| 96 |
| 97 EnumMeta will use the names found in self._member_names as the |
| 98 enumeration member names. |
| 99 |
| 100 """ |
| 101 def __init__(self): |
| 102 super(_EnumDict, self).__init__() |
| 103 self._member_names = [] |
| 104 |
| 105 def __setitem__(self, key, value): |
| 106 """Changes anything not dundered or not a descriptor. |
| 107 |
| 108 If a descriptor is added with the same name as an enum member, the name |
| 109 is removed from _member_names (this may leave a hole in the numerical |
| 110 sequence of values). |
| 111 |
| 112 If an enum member name is used twice, an error is raised; duplicate |
| 113 values are not checked for. |
| 114 |
| 115 Single underscore (sunder) names are reserved. |
| 116 |
| 117 Note: in 3.x __order__ is simply discarded as a not necessary piece |
| 118 leftover from 2.x |
| 119 |
| 120 """ |
| 121 if pyver >= 3.0 and key in ('_order_', '__order__'): |
| 122 return |
| 123 elif key == '__order__': |
| 124 key = '_order_' |
| 125 if _is_sunder(key): |
| 126 if key != '_order_': |
| 127 raise ValueError('_names_ are reserved for future Enum use') |
| 128 elif _is_dunder(key): |
| 129 pass |
| 130 elif key in self._member_names: |
| 131 # descriptor overwriting an enum? |
| 132 raise TypeError('Attempted to reuse key: %r' % key) |
| 133 elif not _is_descriptor(value): |
| 134 if key in self: |
| 135 # enum overwriting a descriptor? |
| 136 raise TypeError('Key already defined as: %r' % self[key]) |
| 137 self._member_names.append(key) |
| 138 super(_EnumDict, self).__setitem__(key, value) |
| 139 |
| 140 |
| 141 # Dummy value for Enum as EnumMeta explicity checks for it, but of course until |
| 142 # EnumMeta finishes running the first time the Enum class doesn't exist. This |
| 143 # is also why there are checks in EnumMeta like `if Enum is not None` |
| 144 Enum = None |
| 145 |
| 146 |
| 147 class EnumMeta(type): |
| 148 """Metaclass for Enum""" |
| 149 @classmethod |
| 150 def __prepare__(metacls, cls, bases): |
| 151 return _EnumDict() |
| 152 |
| 153 def __new__(metacls, cls, bases, classdict): |
| 154 # an Enum class is final once enumeration items have been defined; it |
| 155 # cannot be mixed with other types (int, float, etc.) if it has an |
| 156 # inherited __new__ unless a new __new__ is defined (or the resulting |
| 157 # class will fail). |
| 158 if type(classdict) is dict: |
| 159 original_dict = classdict |
| 160 classdict = _EnumDict() |
| 161 for k, v in original_dict.items(): |
| 162 classdict[k] = v |
| 163 |
| 164 member_type, first_enum = metacls._get_mixins_(bases) |
| 165 __new__, save_new, use_args = metacls._find_new_(classdict, member_type, |
| 166 first_enum) |
| 167 # save enum items into separate mapping so they don't get baked into |
| 168 # the new class |
| 169 members = dict((k, classdict[k]) for k in classdict._member_names) |
| 170 for name in classdict._member_names: |
| 171 del classdict[name] |
| 172 |
| 173 # py2 support for definition order |
| 174 _order_ = classdict.get('_order_') |
| 175 if _order_ is None: |
| 176 if pyver < 3.0: |
| 177 try: |
| 178 _order_ = [name for (name, value) in sorted(members.items(),
key=lambda item: item[1])] |
| 179 except TypeError: |
| 180 _order_ = [name for name in sorted(members.keys())] |
| 181 else: |
| 182 _order_ = classdict._member_names |
| 183 else: |
| 184 del classdict['_order_'] |
| 185 if pyver < 3.0: |
| 186 _order_ = _order_.replace(',', ' ').split() |
| 187 aliases = [name for name in members if name not in _order_] |
| 188 _order_ += aliases |
| 189 |
| 190 # check for illegal enum names (any others?) |
| 191 invalid_names = set(members) & set(['mro']) |
| 192 if invalid_names: |
| 193 raise ValueError('Invalid enum member name(s): %s' % ( |
| 194 ', '.join(invalid_names), )) |
| 195 |
| 196 # save attributes from super classes so we know if we can take |
| 197 # the shortcut of storing members in the class dict |
| 198 base_attributes = set([a for b in bases for a in b.__dict__]) |
| 199 # create our new Enum type |
| 200 enum_class = super(EnumMeta, metacls).__new__(metacls, cls, bases, class
dict) |
| 201 enum_class._member_names_ = [] # names in random order |
| 202 if OrderedDict is not None: |
| 203 enum_class._member_map_ = OrderedDict() |
| 204 else: |
| 205 enum_class._member_map_ = {} # name->value map |
| 206 enum_class._member_type_ = member_type |
| 207 |
| 208 # Reverse value->name map for hashable values. |
| 209 enum_class._value2member_map_ = {} |
| 210 |
| 211 # instantiate them, checking for duplicates as we go |
| 212 # we instantiate first instead of checking for duplicates first in case |
| 213 # a custom __new__ is doing something funky with the values -- such as |
| 214 # auto-numbering ;) |
| 215 if __new__ is None: |
| 216 __new__ = enum_class.__new__ |
| 217 for member_name in _order_: |
| 218 value = members[member_name] |
| 219 if not isinstance(value, tuple): |
| 220 args = (value, ) |
| 221 else: |
| 222 args = value |
| 223 if member_type is tuple: # special case for tuple enums |
| 224 args = (args, ) # wrap it one more time |
| 225 if not use_args or not args: |
| 226 enum_member = __new__(enum_class) |
| 227 if not hasattr(enum_member, '_value_'): |
| 228 enum_member._value_ = value |
| 229 else: |
| 230 enum_member = __new__(enum_class, *args) |
| 231 if not hasattr(enum_member, '_value_'): |
| 232 enum_member._value_ = member_type(*args) |
| 233 value = enum_member._value_ |
| 234 enum_member._name_ = member_name |
| 235 enum_member.__objclass__ = enum_class |
| 236 enum_member.__init__(*args) |
| 237 # If another member with the same value was already defined, the |
| 238 # new member becomes an alias to the existing one. |
| 239 for name, canonical_member in enum_class._member_map_.items(): |
| 240 if canonical_member.value == enum_member._value_: |
| 241 enum_member = canonical_member |
| 242 break |
| 243 else: |
| 244 # Aliases don't appear in member names (only in __members__). |
| 245 enum_class._member_names_.append(member_name) |
| 246 # performance boost for any member that would not shadow |
| 247 # a DynamicClassAttribute (aka _RouteClassAttributeToGetattr) |
| 248 if member_name not in base_attributes: |
| 249 setattr(enum_class, member_name, enum_member) |
| 250 # now add to _member_map_ |
| 251 enum_class._member_map_[member_name] = enum_member |
| 252 try: |
| 253 # This may fail if value is not hashable. We can't add the value |
| 254 # to the map, and by-value lookups for this value will be |
| 255 # linear. |
| 256 enum_class._value2member_map_[value] = enum_member |
| 257 except TypeError: |
| 258 pass |
| 259 |
| 260 |
| 261 # If a custom type is mixed into the Enum, and it does not know how |
| 262 # to pickle itself, pickle.dumps will succeed but pickle.loads will |
| 263 # fail. Rather than have the error show up later and possibly far |
| 264 # from the source, sabotage the pickle protocol for this class so |
| 265 # that pickle.dumps also fails. |
| 266 # |
| 267 # However, if the new class implements its own __reduce_ex__, do not |
| 268 # sabotage -- it's on them to make sure it works correctly. We use |
| 269 # __reduce_ex__ instead of any of the others as it is preferred by |
| 270 # pickle over __reduce__, and it handles all pickle protocols. |
| 271 unpicklable = False |
| 272 if '__reduce_ex__' not in classdict: |
| 273 if member_type is not object: |
| 274 methods = ('__getnewargs_ex__', '__getnewargs__', |
| 275 '__reduce_ex__', '__reduce__') |
| 276 if not any(m in member_type.__dict__ for m in methods): |
| 277 _make_class_unpicklable(enum_class) |
| 278 unpicklable = True |
| 279 |
| 280 |
| 281 # double check that repr and friends are not the mixin's or various |
| 282 # things break (such as pickle) |
| 283 for name in ('__repr__', '__str__', '__format__', '__reduce_ex__'): |
| 284 class_method = getattr(enum_class, name) |
| 285 obj_method = getattr(member_type, name, None) |
| 286 enum_method = getattr(first_enum, name, None) |
| 287 if name not in classdict and class_method is not enum_method: |
| 288 if name == '__reduce_ex__' and unpicklable: |
| 289 continue |
| 290 setattr(enum_class, name, enum_method) |
| 291 |
| 292 # method resolution and int's are not playing nice |
| 293 # Python's less than 2.6 use __cmp__ |
| 294 |
| 295 if pyver < 2.6: |
| 296 |
| 297 if issubclass(enum_class, int): |
| 298 setattr(enum_class, '__cmp__', getattr(int, '__cmp__')) |
| 299 |
| 300 elif pyver < 3.0: |
| 301 |
| 302 if issubclass(enum_class, int): |
| 303 for method in ( |
| 304 '__le__', |
| 305 '__lt__', |
| 306 '__gt__', |
| 307 '__ge__', |
| 308 '__eq__', |
| 309 '__ne__', |
| 310 '__hash__', |
| 311 ): |
| 312 setattr(enum_class, method, getattr(int, method)) |
| 313 |
| 314 # replace any other __new__ with our own (as long as Enum is not None, |
| 315 # anyway) -- again, this is to support pickle |
| 316 if Enum is not None: |
| 317 # if the user defined their own __new__, save it before it gets |
| 318 # clobbered in case they subclass later |
| 319 if save_new: |
| 320 setattr(enum_class, '__member_new__', enum_class.__dict__['__new
__']) |
| 321 setattr(enum_class, '__new__', Enum.__dict__['__new__']) |
| 322 return enum_class |
| 323 |
| 324 def __bool__(cls): |
| 325 """ |
| 326 classes/types should always be True. |
| 327 """ |
| 328 return True |
| 329 |
| 330 def __call__(cls, value, names=None, module=None, type=None, start=1): |
| 331 """Either returns an existing member, or creates a new enum class. |
| 332 |
| 333 This method is used both when an enum class is given a value to match |
| 334 to an enumeration member (i.e. Color(3)) and for the functional API |
| 335 (i.e. Color = Enum('Color', names='red green blue')). |
| 336 |
| 337 When used for the functional API: `module`, if set, will be stored in |
| 338 the new class' __module__ attribute; `type`, if set, will be mixed in |
| 339 as the first base class. |
| 340 |
| 341 Note: if `module` is not set this routine will attempt to discover the |
| 342 calling module by walking the frame stack; if this is unsuccessful |
| 343 the resulting class will not be pickleable. |
| 344 |
| 345 """ |
| 346 if names is None: # simple value lookup |
| 347 return cls.__new__(cls, value) |
| 348 # otherwise, functional API: we're creating a new Enum type |
| 349 return cls._create_(value, names, module=module, type=type, start=start) |
| 350 |
| 351 def __contains__(cls, member): |
| 352 return isinstance(member, cls) and member.name in cls._member_map_ |
| 353 |
| 354 def __delattr__(cls, attr): |
| 355 # nicer error message when someone tries to delete an attribute |
| 356 # (see issue19025). |
| 357 if attr in cls._member_map_: |
| 358 raise AttributeError( |
| 359 "%s: cannot delete Enum member." % cls.__name__) |
| 360 super(EnumMeta, cls).__delattr__(attr) |
| 361 |
| 362 def __dir__(self): |
| 363 return (['__class__', '__doc__', '__members__', '__module__'] + |
| 364 self._member_names_) |
| 365 |
| 366 @property |
| 367 def __members__(cls): |
| 368 """Returns a mapping of member name->value. |
| 369 |
| 370 This mapping lists all enum members, including aliases. Note that this |
| 371 is a copy of the internal mapping. |
| 372 |
| 373 """ |
| 374 return cls._member_map_.copy() |
| 375 |
| 376 def __getattr__(cls, name): |
| 377 """Return the enum member matching `name` |
| 378 |
| 379 We use __getattr__ instead of descriptors or inserting into the enum |
| 380 class' __dict__ in order to support `name` and `value` being both |
| 381 properties for enum members (which live in the class' __dict__) and |
| 382 enum members themselves. |
| 383 |
| 384 """ |
| 385 if _is_dunder(name): |
| 386 raise AttributeError(name) |
| 387 try: |
| 388 return cls._member_map_[name] |
| 389 except KeyError: |
| 390 raise AttributeError(name) |
| 391 |
| 392 def __getitem__(cls, name): |
| 393 return cls._member_map_[name] |
| 394 |
| 395 def __iter__(cls): |
| 396 return (cls._member_map_[name] for name in cls._member_names_) |
| 397 |
| 398 def __reversed__(cls): |
| 399 return (cls._member_map_[name] for name in reversed(cls._member_names_)) |
| 400 |
| 401 def __len__(cls): |
| 402 return len(cls._member_names_) |
| 403 |
| 404 __nonzero__ = __bool__ |
| 405 |
| 406 def __repr__(cls): |
| 407 return "<enum %r>" % cls.__name__ |
| 408 |
| 409 def __setattr__(cls, name, value): |
| 410 """Block attempts to reassign Enum members. |
| 411 |
| 412 A simple assignment to the class namespace only changes one of the |
| 413 several possible ways to get an Enum member from the Enum class, |
| 414 resulting in an inconsistent Enumeration. |
| 415 |
| 416 """ |
| 417 member_map = cls.__dict__.get('_member_map_', {}) |
| 418 if name in member_map: |
| 419 raise AttributeError('Cannot reassign members.') |
| 420 super(EnumMeta, cls).__setattr__(name, value) |
| 421 |
| 422 def _create_(cls, class_name, names=None, module=None, type=None, start=1): |
| 423 """Convenience method to create a new Enum class. |
| 424 |
| 425 `names` can be: |
| 426 |
| 427 * A string containing member names, separated either with spaces or |
| 428 commas. Values are auto-numbered from 1. |
| 429 * An iterable of member names. Values are auto-numbered from 1. |
| 430 * An iterable of (member name, value) pairs. |
| 431 * A mapping of member name -> value. |
| 432 |
| 433 """ |
| 434 if pyver < 3.0: |
| 435 # if class_name is unicode, attempt a conversion to ASCII |
| 436 if isinstance(class_name, unicode): |
| 437 try: |
| 438 class_name = class_name.encode('ascii') |
| 439 except UnicodeEncodeError: |
| 440 raise TypeError('%r is not representable in ASCII' % class_n
ame) |
| 441 metacls = cls.__class__ |
| 442 if type is None: |
| 443 bases = (cls, ) |
| 444 else: |
| 445 bases = (type, cls) |
| 446 classdict = metacls.__prepare__(class_name, bases) |
| 447 _order_ = [] |
| 448 |
| 449 # special processing needed for names? |
| 450 if isinstance(names, basestring): |
| 451 names = names.replace(',', ' ').split() |
| 452 if isinstance(names, (tuple, list)) and isinstance(names[0], basestring)
: |
| 453 names = [(e, i+start) for (i, e) in enumerate(names)] |
| 454 |
| 455 # Here, names is either an iterable of (name, value) or a mapping. |
| 456 item = None # in case names is empty |
| 457 for item in names: |
| 458 if isinstance(item, basestring): |
| 459 member_name, member_value = item, names[item] |
| 460 else: |
| 461 member_name, member_value = item |
| 462 classdict[member_name] = member_value |
| 463 _order_.append(member_name) |
| 464 # only set _order_ in classdict if name/value was not from a mapping |
| 465 if not isinstance(item, basestring): |
| 466 classdict['_order_'] = ' '.join(_order_) |
| 467 enum_class = metacls.__new__(metacls, class_name, bases, classdict) |
| 468 |
| 469 # TODO: replace the frame hack if a blessed way to know the calling |
| 470 # module is ever developed |
| 471 if module is None: |
| 472 try: |
| 473 module = _sys._getframe(2).f_globals['__name__'] |
| 474 except (AttributeError, ValueError): |
| 475 pass |
| 476 if module is None: |
| 477 _make_class_unpicklable(enum_class) |
| 478 else: |
| 479 enum_class.__module__ = module |
| 480 |
| 481 return enum_class |
| 482 |
| 483 @staticmethod |
| 484 def _get_mixins_(bases): |
| 485 """Returns the type for creating enum members, and the first inherited |
| 486 enum class. |
| 487 |
| 488 bases: the tuple of bases that was given to __new__ |
| 489 |
| 490 """ |
| 491 if not bases or Enum is None: |
| 492 return object, Enum |
| 493 |
| 494 |
| 495 # double check that we are not subclassing a class with existing |
| 496 # enumeration members; while we're at it, see if any other data |
| 497 # type has been mixed in so we can use the correct __new__ |
| 498 member_type = first_enum = None |
| 499 for base in bases: |
| 500 if (base is not Enum and |
| 501 issubclass(base, Enum) and |
| 502 base._member_names_): |
| 503 raise TypeError("Cannot extend enumerations") |
| 504 # base is now the last base in bases |
| 505 if not issubclass(base, Enum): |
| 506 raise TypeError("new enumerations must be created as " |
| 507 "`ClassName([mixin_type,] enum_type)`") |
| 508 |
| 509 # get correct mix-in type (either mix-in type of Enum subclass, or |
| 510 # first base if last base is Enum) |
| 511 if not issubclass(bases[0], Enum): |
| 512 member_type = bases[0] # first data type |
| 513 first_enum = bases[-1] # enum type |
| 514 else: |
| 515 for base in bases[0].__mro__: |
| 516 # most common: (IntEnum, int, Enum, object) |
| 517 # possible: (<Enum 'AutoIntEnum'>, <Enum 'IntEnum'>, |
| 518 # <class 'int'>, <Enum 'Enum'>, |
| 519 # <class 'object'>) |
| 520 if issubclass(base, Enum): |
| 521 if first_enum is None: |
| 522 first_enum = base |
| 523 else: |
| 524 if member_type is None: |
| 525 member_type = base |
| 526 |
| 527 return member_type, first_enum |
| 528 |
| 529 if pyver < 3.0: |
| 530 @staticmethod |
| 531 def _find_new_(classdict, member_type, first_enum): |
| 532 """Returns the __new__ to be used for creating the enum members. |
| 533 |
| 534 classdict: the class dictionary given to __new__ |
| 535 member_type: the data type whose __new__ will be used by default |
| 536 first_enum: enumeration to check for an overriding __new__ |
| 537 |
| 538 """ |
| 539 # now find the correct __new__, checking to see of one was defined |
| 540 # by the user; also check earlier enum classes in case a __new__ was |
| 541 # saved as __member_new__ |
| 542 __new__ = classdict.get('__new__', None) |
| 543 if __new__: |
| 544 return None, True, True # __new__, save_new, use_args |
| 545 |
| 546 N__new__ = getattr(None, '__new__') |
| 547 O__new__ = getattr(object, '__new__') |
| 548 if Enum is None: |
| 549 E__new__ = N__new__ |
| 550 else: |
| 551 E__new__ = Enum.__dict__['__new__'] |
| 552 # check all possibles for __member_new__ before falling back to |
| 553 # __new__ |
| 554 for method in ('__member_new__', '__new__'): |
| 555 for possible in (member_type, first_enum): |
| 556 try: |
| 557 target = possible.__dict__[method] |
| 558 except (AttributeError, KeyError): |
| 559 target = getattr(possible, method, None) |
| 560 if target not in [ |
| 561 None, |
| 562 N__new__, |
| 563 O__new__, |
| 564 E__new__, |
| 565 ]: |
| 566 if method == '__member_new__': |
| 567 classdict['__new__'] = target |
| 568 return None, False, True |
| 569 if isinstance(target, staticmethod): |
| 570 target = target.__get__(member_type) |
| 571 __new__ = target |
| 572 break |
| 573 if __new__ is not None: |
| 574 break |
| 575 else: |
| 576 __new__ = object.__new__ |
| 577 |
| 578 # if a non-object.__new__ is used then whatever value/tuple was |
| 579 # assigned to the enum member name will be passed to __new__ and to
the |
| 580 # new enum member's __init__ |
| 581 if __new__ is object.__new__: |
| 582 use_args = False |
| 583 else: |
| 584 use_args = True |
| 585 |
| 586 return __new__, False, use_args |
| 587 else: |
| 588 @staticmethod |
| 589 def _find_new_(classdict, member_type, first_enum): |
| 590 """Returns the __new__ to be used for creating the enum members. |
| 591 |
| 592 classdict: the class dictionary given to __new__ |
| 593 member_type: the data type whose __new__ will be used by default |
| 594 first_enum: enumeration to check for an overriding __new__ |
| 595 |
| 596 """ |
| 597 # now find the correct __new__, checking to see of one was defined |
| 598 # by the user; also check earlier enum classes in case a __new__ was |
| 599 # saved as __member_new__ |
| 600 __new__ = classdict.get('__new__', None) |
| 601 |
| 602 # should __new__ be saved as __member_new__ later? |
| 603 save_new = __new__ is not None |
| 604 |
| 605 if __new__ is None: |
| 606 # check all possibles for __member_new__ before falling back to |
| 607 # __new__ |
| 608 for method in ('__member_new__', '__new__'): |
| 609 for possible in (member_type, first_enum): |
| 610 target = getattr(possible, method, None) |
| 611 if target not in ( |
| 612 None, |
| 613 None.__new__, |
| 614 object.__new__, |
| 615 Enum.__new__, |
| 616 ): |
| 617 __new__ = target |
| 618 break |
| 619 if __new__ is not None: |
| 620 break |
| 621 else: |
| 622 __new__ = object.__new__ |
| 623 |
| 624 # if a non-object.__new__ is used then whatever value/tuple was |
| 625 # assigned to the enum member name will be passed to __new__ and to
the |
| 626 # new enum member's __init__ |
| 627 if __new__ is object.__new__: |
| 628 use_args = False |
| 629 else: |
| 630 use_args = True |
| 631 |
| 632 return __new__, save_new, use_args |
| 633 |
| 634 |
| 635 ######################################################## |
| 636 # In order to support Python 2 and 3 with a single |
| 637 # codebase we have to create the Enum methods separately |
| 638 # and then use the `type(name, bases, dict)` method to |
| 639 # create the class. |
| 640 ######################################################## |
| 641 temp_enum_dict = {} |
| 642 temp_enum_dict['__doc__'] = "Generic enumeration.\n\n Derive from this class
to define new enumerations.\n\n" |
| 643 |
| 644 def __new__(cls, value): |
| 645 # all enum instances are actually created during class construction |
| 646 # without calling this method; this method is called by the metaclass' |
| 647 # __call__ (i.e. Color(3) ), and by pickle |
| 648 if type(value) is cls: |
| 649 # For lookups like Color(Color.red) |
| 650 value = value.value |
| 651 #return value |
| 652 # by-value search for a matching enum member |
| 653 # see if it's in the reverse mapping (for hashable values) |
| 654 try: |
| 655 if value in cls._value2member_map_: |
| 656 return cls._value2member_map_[value] |
| 657 except TypeError: |
| 658 # not there, now do long search -- O(n) behavior |
| 659 for member in cls._member_map_.values(): |
| 660 if member.value == value: |
| 661 return member |
| 662 raise ValueError("%s is not a valid %s" % (value, cls.__name__)) |
| 663 temp_enum_dict['__new__'] = __new__ |
| 664 del __new__ |
| 665 |
| 666 def __repr__(self): |
| 667 return "<%s.%s: %r>" % ( |
| 668 self.__class__.__name__, self._name_, self._value_) |
| 669 temp_enum_dict['__repr__'] = __repr__ |
| 670 del __repr__ |
| 671 |
| 672 def __str__(self): |
| 673 return "%s.%s" % (self.__class__.__name__, self._name_) |
| 674 temp_enum_dict['__str__'] = __str__ |
| 675 del __str__ |
| 676 |
| 677 if pyver >= 3.0: |
| 678 def __dir__(self): |
| 679 added_behavior = [ |
| 680 m |
| 681 for cls in self.__class__.mro() |
| 682 for m in cls.__dict__ |
| 683 if m[0] != '_' and m not in self._member_map_ |
| 684 ] |
| 685 return (['__class__', '__doc__', '__module__', ] + added_behavior) |
| 686 temp_enum_dict['__dir__'] = __dir__ |
| 687 del __dir__ |
| 688 |
| 689 def __format__(self, format_spec): |
| 690 # mixed-in Enums should use the mixed-in type's __format__, otherwise |
| 691 # we can get strange results with the Enum name showing up instead of |
| 692 # the value |
| 693 |
| 694 # pure Enum branch |
| 695 if self._member_type_ is object: |
| 696 cls = str |
| 697 val = str(self) |
| 698 # mix-in branch |
| 699 else: |
| 700 cls = self._member_type_ |
| 701 val = self.value |
| 702 return cls.__format__(val, format_spec) |
| 703 temp_enum_dict['__format__'] = __format__ |
| 704 del __format__ |
| 705 |
| 706 |
| 707 #################################### |
| 708 # Python's less than 2.6 use __cmp__ |
| 709 |
| 710 if pyver < 2.6: |
| 711 |
| 712 def __cmp__(self, other): |
| 713 if type(other) is self.__class__: |
| 714 if self is other: |
| 715 return 0 |
| 716 return -1 |
| 717 return NotImplemented |
| 718 raise TypeError("unorderable types: %s() and %s()" % (self.__class__.__n
ame__, other.__class__.__name__)) |
| 719 temp_enum_dict['__cmp__'] = __cmp__ |
| 720 del __cmp__ |
| 721 |
| 722 else: |
| 723 |
| 724 def __le__(self, other): |
| 725 raise TypeError("unorderable types: %s() <= %s()" % (self.__class__.__na
me__, other.__class__.__name__)) |
| 726 temp_enum_dict['__le__'] = __le__ |
| 727 del __le__ |
| 728 |
| 729 def __lt__(self, other): |
| 730 raise TypeError("unorderable types: %s() < %s()" % (self.__class__.__nam
e__, other.__class__.__name__)) |
| 731 temp_enum_dict['__lt__'] = __lt__ |
| 732 del __lt__ |
| 733 |
| 734 def __ge__(self, other): |
| 735 raise TypeError("unorderable types: %s() >= %s()" % (self.__class__.__na
me__, other.__class__.__name__)) |
| 736 temp_enum_dict['__ge__'] = __ge__ |
| 737 del __ge__ |
| 738 |
| 739 def __gt__(self, other): |
| 740 raise TypeError("unorderable types: %s() > %s()" % (self.__class__.__nam
e__, other.__class__.__name__)) |
| 741 temp_enum_dict['__gt__'] = __gt__ |
| 742 del __gt__ |
| 743 |
| 744 |
| 745 def __eq__(self, other): |
| 746 if type(other) is self.__class__: |
| 747 return self is other |
| 748 return NotImplemented |
| 749 temp_enum_dict['__eq__'] = __eq__ |
| 750 del __eq__ |
| 751 |
| 752 def __ne__(self, other): |
| 753 if type(other) is self.__class__: |
| 754 return self is not other |
| 755 return NotImplemented |
| 756 temp_enum_dict['__ne__'] = __ne__ |
| 757 del __ne__ |
| 758 |
| 759 def __hash__(self): |
| 760 return hash(self._name_) |
| 761 temp_enum_dict['__hash__'] = __hash__ |
| 762 del __hash__ |
| 763 |
| 764 def __reduce_ex__(self, proto): |
| 765 return self.__class__, (self._value_, ) |
| 766 temp_enum_dict['__reduce_ex__'] = __reduce_ex__ |
| 767 del __reduce_ex__ |
| 768 |
| 769 # _RouteClassAttributeToGetattr is used to provide access to the `name` |
| 770 # and `value` properties of enum members while keeping some measure of |
| 771 # protection from modification, while still allowing for an enumeration |
| 772 # to have members named `name` and `value`. This works because enumeration |
| 773 # members are not set directly on the enum class -- __getattr__ is |
| 774 # used to look them up. |
| 775 |
| 776 @_RouteClassAttributeToGetattr |
| 777 def name(self): |
| 778 return self._name_ |
| 779 temp_enum_dict['name'] = name |
| 780 del name |
| 781 |
| 782 @_RouteClassAttributeToGetattr |
| 783 def value(self): |
| 784 return self._value_ |
| 785 temp_enum_dict['value'] = value |
| 786 del value |
| 787 |
| 788 @classmethod |
| 789 def _convert(cls, name, module, filter, source=None): |
| 790 """ |
| 791 Create a new Enum subclass that replaces a collection of global constants |
| 792 """ |
| 793 # convert all constants from source (or module) that pass filter() to |
| 794 # a new Enum called name, and export the enum and its members back to |
| 795 # module; |
| 796 # also, replace the __reduce_ex__ method so unpickling works in |
| 797 # previous Python versions |
| 798 module_globals = vars(_sys.modules[module]) |
| 799 if source: |
| 800 source = vars(source) |
| 801 else: |
| 802 source = module_globals |
| 803 members = dict((name, value) for name, value in source.items() if filter(nam
e)) |
| 804 cls = cls(name, members, module=module) |
| 805 cls.__reduce_ex__ = _reduce_ex_by_name |
| 806 module_globals.update(cls.__members__) |
| 807 module_globals[name] = cls |
| 808 return cls |
| 809 temp_enum_dict['_convert'] = _convert |
| 810 del _convert |
| 811 |
| 812 Enum = EnumMeta('Enum', (object, ), temp_enum_dict) |
| 813 del temp_enum_dict |
| 814 |
| 815 # Enum has now been created |
| 816 ########################### |
| 817 |
| 818 class IntEnum(int, Enum): |
| 819 """Enum where members are also (and must be) ints""" |
| 820 |
| 821 def _reduce_ex_by_name(self, proto): |
| 822 return self.name |
| 823 |
| 824 def unique(enumeration): |
| 825 """Class decorator that ensures only unique members exist in an enumeration.
""" |
| 826 duplicates = [] |
| 827 for name, member in enumeration.__members__.items(): |
| 828 if name != member.name: |
| 829 duplicates.append((name, member.name)) |
| 830 if duplicates: |
| 831 duplicate_names = ', '.join( |
| 832 ["%s -> %s" % (alias, name) for (alias, name) in duplicates] |
| 833 ) |
| 834 raise ValueError('duplicate names found in %r: %s' % |
| 835 (enumeration, duplicate_names) |
| 836 ) |
| 837 return enumeration |
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