| import sys |
| from types import MappingProxyType, DynamicClassAttribute |
| |
| |
| __all__ = [ |
| 'EnumMeta', |
| 'Enum', 'IntEnum', 'StrEnum', '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 _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_sunder(key): |
| if key not in ( |
| '_order_', '_create_pseudo_member_', |
| '_generate_next_value_', '_missing_', '_ignore_', |
| ): |
| raise ValueError(f'_sunder_ names, such as "{key}", 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): |
| # check that previous enum members do not exist |
| metacls._check_for_existing_members(cls, bases) |
| # create the namespace dict |
| enum_dict = _EnumDict() |
| # 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): |
| # 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.' |
| |
| # create our new Enum type |
| enum_class = super().__new__(metacls, cls, bases, classdict) |
| 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): |
| _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, member): |
| if not isinstance(member, Enum): |
| raise TypeError( |
| "unsupported operand type(s) for 'in': '%s' and '%s'" % ( |
| type(member).__qualname__, cls.__class__.__qualname__)) |
| return isinstance(member, cls) and member._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): |
| 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): |
| 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 = [] |
| 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.append(base._member_type_) |
| break |
| elif '__new__' in base.__dict__: |
| if issubclass(base, Enum): |
| continue |
| data_types.append(candidate or base) |
| break |
| else: |
| candidate = base |
| if len(data_types) > 1: |
| raise TypeError('%r: too many data types: %r' % (class_name, data_types)) |
| elif data_types: |
| return data_types[0] |
| 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 |
| 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) |
| ) |
| exc.__context__ = ve_exc |
| raise exc |
| |
| def _generate_next_value_(name, start, count, last_values): |
| 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): |
| 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): |
| # 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__ != Enum.__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 |
| """ |
| |
| |
| class StrEnum(str, Enum): |
| """ |
| Enum where members are also (and must be) strings |
| """ |
| |
| def __new__(cls, *values): |
| if len(values) > 3: |
| raise TypeError('too many arguments for str(): %r' % (values, )) |
| if len(values) == 1: |
| # it must be a string |
| if not isinstance(values[0], str): |
| raise TypeError('%r is not a string' % (values[0], )) |
| if len(values) > 1: |
| # check that encoding argument is a string |
| if not isinstance(values[1], str): |
| raise TypeError('encoding must be a string, not %r' % (values[1], )) |
| if len(values) > 2: |
| # check that errors argument is a string |
| if not isinstance(values[2], str): |
| raise TypeError('errors must be a string, not %r' % (values[2], )) |
| value = str(*values) |
| member = str.__new__(cls, value) |
| member._value_ = value |
| return member |
| |
| __str__ = str.__str__ |
| |
| |
| 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): |
| 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): |
| 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 __iter__(self): |
| members, extra_flags = _decompose(self.__class__, self.value) |
| return (m for m in members if m._value_ != 0) |
| |
| 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): |
| 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): |
| 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): |
| result = self.__class__(~self._value_) |
| return result |
| |
| |
| def _high_bit(value): |
| """returns index of highest bit, or -1 if value is zero or negative""" |
| return value.bit_length() - 1 |
| |
| def unique(enumeration): |
| """Class decorator for enumerations ensuring unique member values.""" |
| duplicates = [] |
| for name, member in enumeration.__members__.items(): |
| if name != member.name: |
| duplicates.append((name, member.name)) |
| if duplicates: |
| alias_details = ', '.join( |
| ["%s -> %s" % (alias, name) for (alias, name) in duplicates]) |
| raise ValueError('duplicate values found in %r: %s' % |
| (enumeration, alias_details)) |
| return enumeration |
| |
| def _decompose(flag, value): |
| """Extract all members from the value.""" |
| # _decompose is only called if the value is not named |
| not_covered = value |
| negative = value < 0 |
| members = [] |
| for member in flag: |
| member_value = member.value |
| if member_value and member_value & value == member_value: |
| members.append(member) |
| not_covered &= ~member_value |
| if not negative: |
| tmp = not_covered |
| while tmp: |
| flag_value = 2 ** _high_bit(tmp) |
| if flag_value in flag._value2member_map_: |
| members.append(flag._value2member_map_[flag_value]) |
| not_covered &= ~flag_value |
| tmp &= ~flag_value |
| if not members and value in flag._value2member_map_: |
| members.append(flag._value2member_map_[value]) |
| members.sort(key=lambda m: m._value_, reverse=True) |
| if len(members) > 1 and members[0].value == value: |
| # we have the breakdown, don't need the value member itself |
| members.pop(0) |
| return members, not_covered |