Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 1 | import sys |
Ethan Furman | e03ea37 | 2013-09-25 07:14:41 -0700 | [diff] [blame] | 2 | from types import MappingProxyType, DynamicClassAttribute |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 3 | |
Ethan Furman | c791507 | 2015-09-17 22:55:40 -0700 | [diff] [blame] | 4 | # try _collections first to reduce startup cost |
Ethan Furman | e5754ab | 2015-09-17 22:03:52 -0700 | [diff] [blame] | 5 | try: |
| 6 | from _collections import OrderedDict |
| 7 | except ImportError: |
| 8 | from collections import OrderedDict |
| 9 | |
| 10 | |
Ethan Furman | c16595e | 2016-09-10 23:36:59 -0700 | [diff] [blame] | 11 | __all__ = [ |
| 12 | 'EnumMeta', |
| 13 | 'Enum', 'IntEnum', 'Flag', 'IntFlag', |
| 14 | 'auto', 'unique', |
| 15 | ] |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 16 | |
| 17 | |
Ethan Furman | 101e074 | 2013-09-15 12:34:36 -0700 | [diff] [blame] | 18 | def _is_descriptor(obj): |
| 19 | """Returns True if obj is a descriptor, False otherwise.""" |
| 20 | return ( |
| 21 | hasattr(obj, '__get__') or |
| 22 | hasattr(obj, '__set__') or |
| 23 | hasattr(obj, '__delete__')) |
| 24 | |
| 25 | |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 26 | def _is_dunder(name): |
| 27 | """Returns True if a __dunder__ name, False otherwise.""" |
| 28 | return (name[:2] == name[-2:] == '__' and |
| 29 | name[2:3] != '_' and |
Ethan Furman | 648f860 | 2013-10-06 17:19:54 -0700 | [diff] [blame] | 30 | name[-3:-2] != '_' and |
| 31 | len(name) > 4) |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 32 | |
| 33 | |
| 34 | def _is_sunder(name): |
| 35 | """Returns True if a _sunder_ name, False otherwise.""" |
| 36 | return (name[0] == name[-1] == '_' and |
| 37 | name[1:2] != '_' and |
Ethan Furman | 648f860 | 2013-10-06 17:19:54 -0700 | [diff] [blame] | 38 | name[-2:-1] != '_' and |
| 39 | len(name) > 2) |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 40 | |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 41 | def _make_class_unpicklable(cls): |
| 42 | """Make the given class un-picklable.""" |
Ethan Furman | ca1b794 | 2014-02-08 11:36:27 -0800 | [diff] [blame] | 43 | def _break_on_call_reduce(self, proto): |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 44 | raise TypeError('%r cannot be pickled' % self) |
Ethan Furman | ca1b794 | 2014-02-08 11:36:27 -0800 | [diff] [blame] | 45 | cls.__reduce_ex__ = _break_on_call_reduce |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 46 | cls.__module__ = '<unknown>' |
| 47 | |
Ethan Furman | 3515dcc | 2016-09-18 13:15:41 -0700 | [diff] [blame] | 48 | _auto_null = object() |
Ethan Furman | c16595e | 2016-09-10 23:36:59 -0700 | [diff] [blame] | 49 | class auto: |
| 50 | """ |
| 51 | Instances are replaced with an appropriate value in Enum class suites. |
| 52 | """ |
Ethan Furman | 3515dcc | 2016-09-18 13:15:41 -0700 | [diff] [blame] | 53 | value = _auto_null |
Ethan Furman | c16595e | 2016-09-10 23:36:59 -0700 | [diff] [blame] | 54 | |
Ethan Furman | 101e074 | 2013-09-15 12:34:36 -0700 | [diff] [blame] | 55 | |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 56 | class _EnumDict(dict): |
Ethan Furman | 101e074 | 2013-09-15 12:34:36 -0700 | [diff] [blame] | 57 | """Track enum member order and ensure member names are not reused. |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 58 | |
| 59 | EnumMeta will use the names found in self._member_names as the |
| 60 | enumeration member names. |
| 61 | |
| 62 | """ |
| 63 | def __init__(self): |
| 64 | super().__init__() |
| 65 | self._member_names = [] |
Ethan Furman | c16595e | 2016-09-10 23:36:59 -0700 | [diff] [blame] | 66 | self._last_values = [] |
Ethan Furman | a4b1bb4 | 2018-01-22 07:56:37 -0800 | [diff] [blame] | 67 | self._ignore = [] |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 68 | |
| 69 | def __setitem__(self, key, value): |
Ethan Furman | 101e074 | 2013-09-15 12:34:36 -0700 | [diff] [blame] | 70 | """Changes anything not dundered or not a descriptor. |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 71 | |
| 72 | If an enum member name is used twice, an error is raised; duplicate |
| 73 | values are not checked for. |
| 74 | |
| 75 | Single underscore (sunder) names are reserved. |
| 76 | |
| 77 | """ |
| 78 | if _is_sunder(key): |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 79 | if key not in ( |
Ethan Furman | 3515dcc | 2016-09-18 13:15:41 -0700 | [diff] [blame] | 80 | '_order_', '_create_pseudo_member_', |
Ethan Furman | a4b1bb4 | 2018-01-22 07:56:37 -0800 | [diff] [blame] | 81 | '_generate_next_value_', '_missing_', '_ignore_', |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 82 | ): |
Ethan Furman | e8e6127 | 2016-08-20 07:19:31 -0700 | [diff] [blame] | 83 | raise ValueError('_names_ are reserved for future Enum use') |
Ethan Furman | c16595e | 2016-09-10 23:36:59 -0700 | [diff] [blame] | 84 | if key == '_generate_next_value_': |
| 85 | setattr(self, '_generate_next_value', value) |
Ethan Furman | a4b1bb4 | 2018-01-22 07:56:37 -0800 | [diff] [blame] | 86 | elif key == '_ignore_': |
| 87 | if isinstance(value, str): |
| 88 | value = value.replace(',',' ').split() |
| 89 | else: |
| 90 | value = list(value) |
| 91 | self._ignore = value |
| 92 | already = set(value) & set(self._member_names) |
| 93 | if already: |
| 94 | raise ValueError('_ignore_ cannot specify already set names: %r' % (already, )) |
Ethan Furman | 101e074 | 2013-09-15 12:34:36 -0700 | [diff] [blame] | 95 | elif _is_dunder(key): |
Ethan Furman | e8e6127 | 2016-08-20 07:19:31 -0700 | [diff] [blame] | 96 | if key == '__order__': |
| 97 | key = '_order_' |
Ethan Furman | 101e074 | 2013-09-15 12:34:36 -0700 | [diff] [blame] | 98 | elif key in self._member_names: |
| 99 | # descriptor overwriting an enum? |
| 100 | raise TypeError('Attempted to reuse key: %r' % key) |
Ethan Furman | a4b1bb4 | 2018-01-22 07:56:37 -0800 | [diff] [blame] | 101 | elif key in self._ignore: |
| 102 | pass |
Ethan Furman | 101e074 | 2013-09-15 12:34:36 -0700 | [diff] [blame] | 103 | elif not _is_descriptor(value): |
| 104 | if key in self: |
| 105 | # enum overwriting a descriptor? |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 106 | raise TypeError('%r already defined as: %r' % (key, self[key])) |
Ethan Furman | c16595e | 2016-09-10 23:36:59 -0700 | [diff] [blame] | 107 | if isinstance(value, auto): |
Ethan Furman | 3515dcc | 2016-09-18 13:15:41 -0700 | [diff] [blame] | 108 | if value.value == _auto_null: |
| 109 | value.value = self._generate_next_value(key, 1, len(self._member_names), self._last_values[:]) |
| 110 | value = value.value |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 111 | self._member_names.append(key) |
Ethan Furman | c16595e | 2016-09-10 23:36:59 -0700 | [diff] [blame] | 112 | self._last_values.append(value) |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 113 | super().__setitem__(key, value) |
| 114 | |
| 115 | |
Ezio Melotti | 9a3777e | 2013-08-17 15:53:55 +0300 | [diff] [blame] | 116 | # Dummy value for Enum as EnumMeta explicitly checks for it, but of course |
| 117 | # until EnumMeta finishes running the first time the Enum class doesn't exist. |
| 118 | # This is also why there are checks in EnumMeta like `if Enum is not None` |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 119 | Enum = None |
| 120 | |
Ethan Furman | 332dbc7 | 2016-08-20 00:00:52 -0700 | [diff] [blame] | 121 | |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 122 | class EnumMeta(type): |
| 123 | """Metaclass for Enum""" |
| 124 | @classmethod |
Ethan Furman | 332dbc7 | 2016-08-20 00:00:52 -0700 | [diff] [blame] | 125 | def __prepare__(metacls, cls, bases): |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 126 | # create the namespace dict |
| 127 | enum_dict = _EnumDict() |
| 128 | # inherit previous flags and _generate_next_value_ function |
| 129 | member_type, first_enum = metacls._get_mixins_(bases) |
| 130 | if first_enum is not None: |
| 131 | enum_dict['_generate_next_value_'] = getattr(first_enum, '_generate_next_value_', None) |
| 132 | return enum_dict |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 133 | |
Ethan Furman | 65a5a47 | 2016-09-01 23:55:19 -0700 | [diff] [blame] | 134 | def __new__(metacls, cls, bases, classdict): |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 135 | # an Enum class is final once enumeration items have been defined; it |
| 136 | # cannot be mixed with other types (int, float, etc.) if it has an |
| 137 | # inherited __new__ unless a new __new__ is defined (or the resulting |
| 138 | # class will fail). |
Ethan Furman | a4b1bb4 | 2018-01-22 07:56:37 -0800 | [diff] [blame] | 139 | # |
| 140 | # remove any keys listed in _ignore_ |
| 141 | classdict.setdefault('_ignore_', []).append('_ignore_') |
| 142 | ignore = classdict['_ignore_'] |
| 143 | for key in ignore: |
| 144 | classdict.pop(key, None) |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 145 | member_type, first_enum = metacls._get_mixins_(bases) |
| 146 | __new__, save_new, use_args = metacls._find_new_(classdict, member_type, |
| 147 | first_enum) |
| 148 | |
| 149 | # save enum items into separate mapping so they don't get baked into |
| 150 | # the new class |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 151 | enum_members = {k: classdict[k] for k in classdict._member_names} |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 152 | for name in classdict._member_names: |
| 153 | del classdict[name] |
| 154 | |
Ethan Furman | e8e6127 | 2016-08-20 07:19:31 -0700 | [diff] [blame] | 155 | # adjust the sunders |
| 156 | _order_ = classdict.pop('_order_', None) |
| 157 | |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 158 | # check for illegal enum names (any others?) |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 159 | invalid_names = set(enum_members) & {'mro', } |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 160 | if invalid_names: |
| 161 | raise ValueError('Invalid enum member name: {0}'.format( |
| 162 | ','.join(invalid_names))) |
| 163 | |
Ethan Furman | 48a724f | 2015-04-11 23:23:06 -0700 | [diff] [blame] | 164 | # create a default docstring if one has not been provided |
| 165 | if '__doc__' not in classdict: |
| 166 | classdict['__doc__'] = 'An enumeration.' |
| 167 | |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 168 | # create our new Enum type |
| 169 | enum_class = super().__new__(metacls, cls, bases, classdict) |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 170 | enum_class._member_names_ = [] # names in definition order |
| 171 | enum_class._member_map_ = OrderedDict() # name->value map |
Ethan Furman | 5e5a823 | 2013-08-04 08:42:23 -0700 | [diff] [blame] | 172 | enum_class._member_type_ = member_type |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 173 | |
Ethan Furman | 354ecf1 | 2015-03-11 08:43:12 -0700 | [diff] [blame] | 174 | # save attributes from super classes so we know if we can take |
| 175 | # the shortcut of storing members in the class dict |
Ethan Furman | 3803ad4 | 2016-05-01 10:03:53 -0700 | [diff] [blame] | 176 | base_attributes = {a for b in enum_class.mro() for a in b.__dict__} |
Ethan Furman | 354ecf1 | 2015-03-11 08:43:12 -0700 | [diff] [blame] | 177 | |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 178 | # Reverse value->name map for hashable values. |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 179 | enum_class._value2member_map_ = {} |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 180 | |
Ethan Furman | 2da9504 | 2014-03-03 12:42:52 -0800 | [diff] [blame] | 181 | # If a custom type is mixed into the Enum, and it does not know how |
| 182 | # to pickle itself, pickle.dumps will succeed but pickle.loads will |
| 183 | # fail. Rather than have the error show up later and possibly far |
| 184 | # from the source, sabotage the pickle protocol for this class so |
| 185 | # that pickle.dumps also fails. |
| 186 | # |
| 187 | # However, if the new class implements its own __reduce_ex__, do not |
| 188 | # sabotage -- it's on them to make sure it works correctly. We use |
| 189 | # __reduce_ex__ instead of any of the others as it is preferred by |
| 190 | # pickle over __reduce__, and it handles all pickle protocols. |
| 191 | if '__reduce_ex__' not in classdict: |
Ethan Furman | dc87052 | 2014-02-18 12:37:12 -0800 | [diff] [blame] | 192 | if member_type is not object: |
| 193 | methods = ('__getnewargs_ex__', '__getnewargs__', |
| 194 | '__reduce_ex__', '__reduce__') |
Ethan Furman | 2da9504 | 2014-03-03 12:42:52 -0800 | [diff] [blame] | 195 | if not any(m in member_type.__dict__ for m in methods): |
Ethan Furman | dc87052 | 2014-02-18 12:37:12 -0800 | [diff] [blame] | 196 | _make_class_unpicklable(enum_class) |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 197 | |
| 198 | # instantiate them, checking for duplicates as we go |
| 199 | # we instantiate first instead of checking for duplicates first in case |
| 200 | # a custom __new__ is doing something funky with the values -- such as |
| 201 | # auto-numbering ;) |
| 202 | for member_name in classdict._member_names: |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 203 | value = enum_members[member_name] |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 204 | if not isinstance(value, tuple): |
| 205 | args = (value, ) |
| 206 | else: |
| 207 | args = value |
| 208 | if member_type is tuple: # special case for tuple enums |
| 209 | args = (args, ) # wrap it one more time |
| 210 | if not use_args: |
| 211 | enum_member = __new__(enum_class) |
Ethan Furman | b41803e | 2013-07-25 13:50:45 -0700 | [diff] [blame] | 212 | if not hasattr(enum_member, '_value_'): |
| 213 | enum_member._value_ = value |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 214 | else: |
| 215 | enum_member = __new__(enum_class, *args) |
Ethan Furman | b41803e | 2013-07-25 13:50:45 -0700 | [diff] [blame] | 216 | if not hasattr(enum_member, '_value_'): |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 217 | if member_type is object: |
| 218 | enum_member._value_ = value |
| 219 | else: |
| 220 | enum_member._value_ = member_type(*args) |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 221 | value = enum_member._value_ |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 222 | enum_member._name_ = member_name |
Ethan Furman | c850f34 | 2013-09-15 16:59:35 -0700 | [diff] [blame] | 223 | enum_member.__objclass__ = enum_class |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 224 | enum_member.__init__(*args) |
| 225 | # If another member with the same value was already defined, the |
| 226 | # new member becomes an alias to the existing one. |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 227 | for name, canonical_member in enum_class._member_map_.items(): |
Ethan Furman | 0081f23 | 2014-09-16 17:31:23 -0700 | [diff] [blame] | 228 | if canonical_member._value_ == enum_member._value_: |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 229 | enum_member = canonical_member |
| 230 | break |
| 231 | else: |
| 232 | # Aliases don't appear in member names (only in __members__). |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 233 | enum_class._member_names_.append(member_name) |
Ethan Furman | 354ecf1 | 2015-03-11 08:43:12 -0700 | [diff] [blame] | 234 | # performance boost for any member that would not shadow |
| 235 | # a DynamicClassAttribute |
| 236 | if member_name not in base_attributes: |
| 237 | setattr(enum_class, member_name, enum_member) |
| 238 | # now add to _member_map_ |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 239 | enum_class._member_map_[member_name] = enum_member |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 240 | try: |
| 241 | # This may fail if value is not hashable. We can't add the value |
| 242 | # to the map, and by-value lookups for this value will be |
| 243 | # linear. |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 244 | enum_class._value2member_map_[value] = enum_member |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 245 | except TypeError: |
| 246 | pass |
| 247 | |
| 248 | # double check that repr and friends are not the mixin's or various |
| 249 | # things break (such as pickle) |
Ethan Furman | dc87052 | 2014-02-18 12:37:12 -0800 | [diff] [blame] | 250 | for name in ('__repr__', '__str__', '__format__', '__reduce_ex__'): |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 251 | class_method = getattr(enum_class, name) |
| 252 | obj_method = getattr(member_type, name, None) |
| 253 | enum_method = getattr(first_enum, name, None) |
| 254 | if obj_method is not None and obj_method is class_method: |
| 255 | setattr(enum_class, name, enum_method) |
| 256 | |
| 257 | # replace any other __new__ with our own (as long as Enum is not None, |
| 258 | # anyway) -- again, this is to support pickle |
| 259 | if Enum is not None: |
| 260 | # if the user defined their own __new__, save it before it gets |
| 261 | # clobbered in case they subclass later |
| 262 | if save_new: |
| 263 | enum_class.__new_member__ = __new__ |
| 264 | enum_class.__new__ = Enum.__new__ |
Ethan Furman | e8e6127 | 2016-08-20 07:19:31 -0700 | [diff] [blame] | 265 | |
| 266 | # py3 support for definition order (helps keep py2/py3 code in sync) |
| 267 | if _order_ is not None: |
| 268 | if isinstance(_order_, str): |
| 269 | _order_ = _order_.replace(',', ' ').split() |
| 270 | if _order_ != enum_class._member_names_: |
| 271 | raise TypeError('member order does not match _order_') |
| 272 | |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 273 | return enum_class |
| 274 | |
Ethan Furman | 5de67b1 | 2016-04-13 23:52:09 -0700 | [diff] [blame] | 275 | def __bool__(self): |
| 276 | """ |
| 277 | classes/types should always be True. |
| 278 | """ |
| 279 | return True |
| 280 | |
Ethan Furman | d9925a1 | 2014-09-16 20:35:55 -0700 | [diff] [blame] | 281 | def __call__(cls, value, names=None, *, module=None, qualname=None, type=None, start=1): |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 282 | """Either returns an existing member, or creates a new enum class. |
| 283 | |
| 284 | This method is used both when an enum class is given a value to match |
| 285 | to an enumeration member (i.e. Color(3)) and for the functional API |
Ethan Furman | 23bb6f4 | 2016-11-21 09:22:05 -0800 | [diff] [blame] | 286 | (i.e. Color = Enum('Color', names='RED GREEN BLUE')). |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 287 | |
Ethan Furman | 2da9504 | 2014-03-03 12:42:52 -0800 | [diff] [blame] | 288 | When used for the functional API: |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 289 | |
Ethan Furman | 2da9504 | 2014-03-03 12:42:52 -0800 | [diff] [blame] | 290 | `value` will be the name of the new class. |
| 291 | |
| 292 | `names` should be either a string of white-space/comma delimited names |
Ethan Furman | d9925a1 | 2014-09-16 20:35:55 -0700 | [diff] [blame] | 293 | (values will start at `start`), or an iterator/mapping of name, value pairs. |
Ethan Furman | 2da9504 | 2014-03-03 12:42:52 -0800 | [diff] [blame] | 294 | |
| 295 | `module` should be set to the module this class is being created in; |
| 296 | if it is not set, an attempt to find that module will be made, but if |
| 297 | it fails the class will not be picklable. |
| 298 | |
| 299 | `qualname` should be set to the actual location this class can be found |
| 300 | at in its module; by default it is set to the global scope. If this is |
| 301 | not correct, unpickling will fail in some circumstances. |
| 302 | |
| 303 | `type`, if set, will be mixed in as the first base class. |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 304 | |
| 305 | """ |
| 306 | if names is None: # simple value lookup |
| 307 | return cls.__new__(cls, value) |
| 308 | # otherwise, functional API: we're creating a new Enum type |
Ethan Furman | d9925a1 | 2014-09-16 20:35:55 -0700 | [diff] [blame] | 309 | return cls._create_(value, names, module=module, qualname=qualname, type=type, start=start) |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 310 | |
| 311 | def __contains__(cls, member): |
Ethan Furman | 0081f23 | 2014-09-16 17:31:23 -0700 | [diff] [blame] | 312 | return isinstance(member, cls) and member._name_ in cls._member_map_ |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 313 | |
Ethan Furman | 64a9972 | 2013-09-22 16:18:19 -0700 | [diff] [blame] | 314 | def __delattr__(cls, attr): |
| 315 | # nicer error message when someone tries to delete an attribute |
| 316 | # (see issue19025). |
| 317 | if attr in cls._member_map_: |
| 318 | raise AttributeError( |
| 319 | "%s: cannot delete Enum member." % cls.__name__) |
| 320 | super().__delattr__(attr) |
| 321 | |
Ethan Furman | 388a392 | 2013-08-12 06:51:41 -0700 | [diff] [blame] | 322 | def __dir__(self): |
Ethan Furman | 64a9972 | 2013-09-22 16:18:19 -0700 | [diff] [blame] | 323 | return (['__class__', '__doc__', '__members__', '__module__'] + |
| 324 | self._member_names_) |
Ethan Furman | 388a392 | 2013-08-12 06:51:41 -0700 | [diff] [blame] | 325 | |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 326 | def __getattr__(cls, name): |
| 327 | """Return the enum member matching `name` |
| 328 | |
| 329 | We use __getattr__ instead of descriptors or inserting into the enum |
| 330 | class' __dict__ in order to support `name` and `value` being both |
| 331 | properties for enum members (which live in the class' __dict__) and |
| 332 | enum members themselves. |
| 333 | |
| 334 | """ |
| 335 | if _is_dunder(name): |
| 336 | raise AttributeError(name) |
| 337 | try: |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 338 | return cls._member_map_[name] |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 339 | except KeyError: |
| 340 | raise AttributeError(name) from None |
| 341 | |
| 342 | def __getitem__(cls, name): |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 343 | return cls._member_map_[name] |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 344 | |
| 345 | def __iter__(cls): |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 346 | return (cls._member_map_[name] for name in cls._member_names_) |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 347 | |
| 348 | def __len__(cls): |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 349 | return len(cls._member_names_) |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 350 | |
Ethan Furman | 2131a4a | 2013-09-14 18:11:24 -0700 | [diff] [blame] | 351 | @property |
| 352 | def __members__(cls): |
| 353 | """Returns a mapping of member name->value. |
| 354 | |
| 355 | This mapping lists all enum members, including aliases. Note that this |
| 356 | is a read-only view of the internal mapping. |
| 357 | |
| 358 | """ |
| 359 | return MappingProxyType(cls._member_map_) |
| 360 | |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 361 | def __repr__(cls): |
| 362 | return "<enum %r>" % cls.__name__ |
| 363 | |
Ethan Furman | 2131a4a | 2013-09-14 18:11:24 -0700 | [diff] [blame] | 364 | def __reversed__(cls): |
| 365 | return (cls._member_map_[name] for name in reversed(cls._member_names_)) |
| 366 | |
Ethan Furman | f203f2d | 2013-09-06 07:16:48 -0700 | [diff] [blame] | 367 | def __setattr__(cls, name, value): |
| 368 | """Block attempts to reassign Enum members. |
| 369 | |
| 370 | A simple assignment to the class namespace only changes one of the |
| 371 | several possible ways to get an Enum member from the Enum class, |
| 372 | resulting in an inconsistent Enumeration. |
| 373 | |
| 374 | """ |
| 375 | member_map = cls.__dict__.get('_member_map_', {}) |
| 376 | if name in member_map: |
| 377 | raise AttributeError('Cannot reassign members.') |
| 378 | super().__setattr__(name, value) |
| 379 | |
Ethan Furman | d9925a1 | 2014-09-16 20:35:55 -0700 | [diff] [blame] | 380 | def _create_(cls, class_name, names=None, *, module=None, qualname=None, type=None, start=1): |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 381 | """Convenience method to create a new Enum class. |
| 382 | |
| 383 | `names` can be: |
| 384 | |
| 385 | * A string containing member names, separated either with spaces or |
Ethan Furman | d9925a1 | 2014-09-16 20:35:55 -0700 | [diff] [blame] | 386 | commas. Values are incremented by 1 from `start`. |
| 387 | * An iterable of member names. Values are incremented by 1 from `start`. |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 388 | * An iterable of (member name, value) pairs. |
Ethan Furman | d9925a1 | 2014-09-16 20:35:55 -0700 | [diff] [blame] | 389 | * A mapping of member name -> value pairs. |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 390 | |
| 391 | """ |
| 392 | metacls = cls.__class__ |
| 393 | bases = (cls, ) if type is None else (type, cls) |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 394 | _, first_enum = cls._get_mixins_(bases) |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 395 | classdict = metacls.__prepare__(class_name, bases) |
| 396 | |
| 397 | # special processing needed for names? |
| 398 | if isinstance(names, str): |
| 399 | names = names.replace(',', ' ').split() |
Dong-hee Na | dcc8ce4 | 2017-06-22 01:52:32 +0900 | [diff] [blame] | 400 | if isinstance(names, (tuple, list)) and names and isinstance(names[0], str): |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 401 | original_names, names = names, [] |
Ethan Furman | c16595e | 2016-09-10 23:36:59 -0700 | [diff] [blame] | 402 | last_values = [] |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 403 | for count, name in enumerate(original_names): |
Ethan Furman | c16595e | 2016-09-10 23:36:59 -0700 | [diff] [blame] | 404 | value = first_enum._generate_next_value_(name, start, count, last_values[:]) |
| 405 | last_values.append(value) |
| 406 | names.append((name, value)) |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 407 | |
| 408 | # Here, names is either an iterable of (name, value) or a mapping. |
| 409 | for item in names: |
| 410 | if isinstance(item, str): |
| 411 | member_name, member_value = item, names[item] |
| 412 | else: |
| 413 | member_name, member_value = item |
| 414 | classdict[member_name] = member_value |
| 415 | enum_class = metacls.__new__(metacls, class_name, bases, classdict) |
| 416 | |
| 417 | # TODO: replace the frame hack if a blessed way to know the calling |
| 418 | # module is ever developed |
| 419 | if module is None: |
| 420 | try: |
| 421 | module = sys._getframe(2).f_globals['__name__'] |
| 422 | except (AttributeError, ValueError) as exc: |
| 423 | pass |
| 424 | if module is None: |
| 425 | _make_class_unpicklable(enum_class) |
| 426 | else: |
| 427 | enum_class.__module__ = module |
Ethan Furman | ca1b794 | 2014-02-08 11:36:27 -0800 | [diff] [blame] | 428 | if qualname is not None: |
| 429 | enum_class.__qualname__ = qualname |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 430 | |
| 431 | return enum_class |
| 432 | |
| 433 | @staticmethod |
| 434 | def _get_mixins_(bases): |
| 435 | """Returns the type for creating enum members, and the first inherited |
| 436 | enum class. |
| 437 | |
| 438 | bases: the tuple of bases that was given to __new__ |
| 439 | |
| 440 | """ |
| 441 | if not bases: |
| 442 | return object, Enum |
| 443 | |
| 444 | # double check that we are not subclassing a class with existing |
| 445 | # enumeration members; while we're at it, see if any other data |
| 446 | # type has been mixed in so we can use the correct __new__ |
| 447 | member_type = first_enum = None |
| 448 | for base in bases: |
| 449 | if (base is not Enum and |
| 450 | issubclass(base, Enum) and |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 451 | base._member_names_): |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 452 | raise TypeError("Cannot extend enumerations") |
| 453 | # base is now the last base in bases |
| 454 | if not issubclass(base, Enum): |
| 455 | raise TypeError("new enumerations must be created as " |
| 456 | "`ClassName([mixin_type,] enum_type)`") |
| 457 | |
| 458 | # get correct mix-in type (either mix-in type of Enum subclass, or |
| 459 | # first base if last base is Enum) |
| 460 | if not issubclass(bases[0], Enum): |
| 461 | member_type = bases[0] # first data type |
| 462 | first_enum = bases[-1] # enum type |
| 463 | else: |
| 464 | for base in bases[0].__mro__: |
| 465 | # most common: (IntEnum, int, Enum, object) |
| 466 | # possible: (<Enum 'AutoIntEnum'>, <Enum 'IntEnum'>, |
| 467 | # <class 'int'>, <Enum 'Enum'>, |
| 468 | # <class 'object'>) |
| 469 | if issubclass(base, Enum): |
| 470 | if first_enum is None: |
| 471 | first_enum = base |
| 472 | else: |
| 473 | if member_type is None: |
| 474 | member_type = base |
| 475 | |
| 476 | return member_type, first_enum |
| 477 | |
| 478 | @staticmethod |
| 479 | def _find_new_(classdict, member_type, first_enum): |
| 480 | """Returns the __new__ to be used for creating the enum members. |
| 481 | |
| 482 | classdict: the class dictionary given to __new__ |
| 483 | member_type: the data type whose __new__ will be used by default |
| 484 | first_enum: enumeration to check for an overriding __new__ |
| 485 | |
| 486 | """ |
| 487 | # now find the correct __new__, checking to see of one was defined |
| 488 | # by the user; also check earlier enum classes in case a __new__ was |
| 489 | # saved as __new_member__ |
| 490 | __new__ = classdict.get('__new__', None) |
| 491 | |
| 492 | # should __new__ be saved as __new_member__ later? |
| 493 | save_new = __new__ is not None |
| 494 | |
| 495 | if __new__ is None: |
| 496 | # check all possibles for __new_member__ before falling back to |
| 497 | # __new__ |
| 498 | for method in ('__new_member__', '__new__'): |
| 499 | for possible in (member_type, first_enum): |
| 500 | target = getattr(possible, method, None) |
| 501 | if target not in { |
| 502 | None, |
| 503 | None.__new__, |
| 504 | object.__new__, |
| 505 | Enum.__new__, |
| 506 | }: |
| 507 | __new__ = target |
| 508 | break |
| 509 | if __new__ is not None: |
| 510 | break |
| 511 | else: |
| 512 | __new__ = object.__new__ |
| 513 | |
| 514 | # if a non-object.__new__ is used then whatever value/tuple was |
| 515 | # assigned to the enum member name will be passed to __new__ and to the |
| 516 | # new enum member's __init__ |
| 517 | if __new__ is object.__new__: |
| 518 | use_args = False |
| 519 | else: |
| 520 | use_args = True |
| 521 | |
| 522 | return __new__, save_new, use_args |
| 523 | |
| 524 | |
| 525 | class Enum(metaclass=EnumMeta): |
| 526 | """Generic enumeration. |
| 527 | |
| 528 | Derive from this class to define new enumerations. |
| 529 | |
| 530 | """ |
| 531 | def __new__(cls, value): |
| 532 | # all enum instances are actually created during class construction |
| 533 | # without calling this method; this method is called by the metaclass' |
| 534 | # __call__ (i.e. Color(3) ), and by pickle |
| 535 | if type(value) is cls: |
Ethan Furman | 23bb6f4 | 2016-11-21 09:22:05 -0800 | [diff] [blame] | 536 | # For lookups like Color(Color.RED) |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 537 | return value |
| 538 | # by-value search for a matching enum member |
| 539 | # see if it's in the reverse mapping (for hashable values) |
Ethan Furman | 2aa2732 | 2013-07-19 19:35:56 -0700 | [diff] [blame] | 540 | try: |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 541 | if value in cls._value2member_map_: |
| 542 | return cls._value2member_map_[value] |
Ethan Furman | 2aa2732 | 2013-07-19 19:35:56 -0700 | [diff] [blame] | 543 | except TypeError: |
| 544 | # not there, now do long search -- O(n) behavior |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 545 | for member in cls._member_map_.values(): |
Ethan Furman | 0081f23 | 2014-09-16 17:31:23 -0700 | [diff] [blame] | 546 | if member._value_ == value: |
Ethan Furman | 2aa2732 | 2013-07-19 19:35:56 -0700 | [diff] [blame] | 547 | return member |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 548 | # still not found -- try _missing_ hook |
| 549 | return cls._missing_(value) |
| 550 | |
Ethan Furman | c16595e | 2016-09-10 23:36:59 -0700 | [diff] [blame] | 551 | def _generate_next_value_(name, start, count, last_values): |
| 552 | for last_value in reversed(last_values): |
| 553 | try: |
| 554 | return last_value + 1 |
| 555 | except TypeError: |
| 556 | pass |
| 557 | else: |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 558 | return start |
Ethan Furman | c16595e | 2016-09-10 23:36:59 -0700 | [diff] [blame] | 559 | |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 560 | @classmethod |
| 561 | def _missing_(cls, value): |
Ethan Furman | 0081f23 | 2014-09-16 17:31:23 -0700 | [diff] [blame] | 562 | raise ValueError("%r is not a valid %s" % (value, cls.__name__)) |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 563 | |
| 564 | def __repr__(self): |
| 565 | return "<%s.%s: %r>" % ( |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 566 | self.__class__.__name__, self._name_, self._value_) |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 567 | |
| 568 | def __str__(self): |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 569 | return "%s.%s" % (self.__class__.__name__, self._name_) |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 570 | |
Ethan Furman | 388a392 | 2013-08-12 06:51:41 -0700 | [diff] [blame] | 571 | def __dir__(self): |
Ethan Furman | 0ae550b | 2014-10-14 08:58:32 -0700 | [diff] [blame] | 572 | added_behavior = [ |
| 573 | m |
| 574 | for cls in self.__class__.mro() |
| 575 | for m in cls.__dict__ |
Ethan Furman | 354ecf1 | 2015-03-11 08:43:12 -0700 | [diff] [blame] | 576 | if m[0] != '_' and m not in self._member_map_ |
Ethan Furman | 0ae550b | 2014-10-14 08:58:32 -0700 | [diff] [blame] | 577 | ] |
Ethan Furman | ec5f8eb | 2014-10-21 13:40:35 -0700 | [diff] [blame] | 578 | return (['__class__', '__doc__', '__module__'] + added_behavior) |
Ethan Furman | 388a392 | 2013-08-12 06:51:41 -0700 | [diff] [blame] | 579 | |
Ethan Furman | ec15a82 | 2013-08-31 19:17:41 -0700 | [diff] [blame] | 580 | def __format__(self, format_spec): |
| 581 | # mixed-in Enums should use the mixed-in type's __format__, otherwise |
| 582 | # we can get strange results with the Enum name showing up instead of |
| 583 | # the value |
| 584 | |
| 585 | # pure Enum branch |
| 586 | if self._member_type_ is object: |
| 587 | cls = str |
| 588 | val = str(self) |
| 589 | # mix-in branch |
| 590 | else: |
| 591 | cls = self._member_type_ |
Ethan Furman | 0081f23 | 2014-09-16 17:31:23 -0700 | [diff] [blame] | 592 | val = self._value_ |
Ethan Furman | ec15a82 | 2013-08-31 19:17:41 -0700 | [diff] [blame] | 593 | return cls.__format__(val, format_spec) |
| 594 | |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 595 | def __hash__(self): |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 596 | return hash(self._name_) |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 597 | |
Ethan Furman | ca1b794 | 2014-02-08 11:36:27 -0800 | [diff] [blame] | 598 | def __reduce_ex__(self, proto): |
Ethan Furman | dc87052 | 2014-02-18 12:37:12 -0800 | [diff] [blame] | 599 | return self.__class__, (self._value_, ) |
Ethan Furman | ca1b794 | 2014-02-08 11:36:27 -0800 | [diff] [blame] | 600 | |
Ethan Furman | 33918c1 | 2013-09-27 23:02:02 -0700 | [diff] [blame] | 601 | # DynamicClassAttribute is used to provide access to the `name` and |
| 602 | # `value` properties of enum members while keeping some measure of |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 603 | # protection from modification, while still allowing for an enumeration |
| 604 | # to have members named `name` and `value`. This works because enumeration |
| 605 | # members are not set directly on the enum class -- __getattr__ is |
| 606 | # used to look them up. |
| 607 | |
Ethan Furman | e03ea37 | 2013-09-25 07:14:41 -0700 | [diff] [blame] | 608 | @DynamicClassAttribute |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 609 | def name(self): |
Ethan Furman | c850f34 | 2013-09-15 16:59:35 -0700 | [diff] [blame] | 610 | """The name of the Enum member.""" |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 611 | return self._name_ |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 612 | |
Ethan Furman | e03ea37 | 2013-09-25 07:14:41 -0700 | [diff] [blame] | 613 | @DynamicClassAttribute |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 614 | def value(self): |
Ethan Furman | c850f34 | 2013-09-15 16:59:35 -0700 | [diff] [blame] | 615 | """The value of the Enum member.""" |
Ethan Furman | 520ad57 | 2013-07-19 19:47:21 -0700 | [diff] [blame] | 616 | return self._value_ |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 617 | |
Ethan Furman | 24e837f | 2015-03-18 17:27:57 -0700 | [diff] [blame] | 618 | @classmethod |
| 619 | def _convert(cls, name, module, filter, source=None): |
| 620 | """ |
| 621 | Create a new Enum subclass that replaces a collection of global constants |
| 622 | """ |
| 623 | # convert all constants from source (or module) that pass filter() to |
| 624 | # a new Enum called name, and export the enum and its members back to |
| 625 | # module; |
| 626 | # also, replace the __reduce_ex__ method so unpickling works in |
| 627 | # previous Python versions |
| 628 | module_globals = vars(sys.modules[module]) |
| 629 | if source: |
| 630 | source = vars(source) |
| 631 | else: |
| 632 | source = module_globals |
Gregory P. Smith ext:(%20%5BGoogle%20Inc.%5D) | 6f20bd6 | 2016-06-03 19:14:52 +0000 | [diff] [blame] | 633 | # We use an OrderedDict of sorted source keys so that the |
| 634 | # _value2member_map is populated in the same order every time |
| 635 | # for a consistent reverse mapping of number to name when there |
| 636 | # are multiple names for the same number rather than varying |
| 637 | # between runs due to hash randomization of the module dictionary. |
Ethan Furman | 06339e7 | 2016-09-11 13:25:26 -0700 | [diff] [blame] | 638 | members = [ |
| 639 | (name, source[name]) |
| 640 | for name in source.keys() |
| 641 | if filter(name)] |
| 642 | try: |
| 643 | # sort by value |
| 644 | members.sort(key=lambda t: (t[1], t[0])) |
| 645 | except TypeError: |
| 646 | # unless some values aren't comparable, in which case sort by name |
| 647 | members.sort(key=lambda t: t[0]) |
Ethan Furman | 24e837f | 2015-03-18 17:27:57 -0700 | [diff] [blame] | 648 | cls = cls(name, members, module=module) |
| 649 | cls.__reduce_ex__ = _reduce_ex_by_name |
| 650 | module_globals.update(cls.__members__) |
| 651 | module_globals[name] = cls |
| 652 | return cls |
| 653 | |
Ethan Furman | 6b3d64a | 2013-06-14 16:55:46 -0700 | [diff] [blame] | 654 | |
| 655 | class IntEnum(int, Enum): |
| 656 | """Enum where members are also (and must be) ints""" |
Ethan Furman | f24bb35 | 2013-07-18 17:05:39 -0700 | [diff] [blame] | 657 | |
| 658 | |
Ethan Furman | 24e837f | 2015-03-18 17:27:57 -0700 | [diff] [blame] | 659 | def _reduce_ex_by_name(self, proto): |
| 660 | return self.name |
| 661 | |
Ethan Furman | 65a5a47 | 2016-09-01 23:55:19 -0700 | [diff] [blame] | 662 | class Flag(Enum): |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 663 | """Support for flags""" |
Ethan Furman | c16595e | 2016-09-10 23:36:59 -0700 | [diff] [blame] | 664 | |
| 665 | def _generate_next_value_(name, start, count, last_values): |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 666 | """ |
| 667 | Generate the next value when not given. |
| 668 | |
| 669 | name: the name of the member |
| 670 | start: the initital start value or None |
| 671 | count: the number of existing members |
| 672 | last_value: the last value assigned or None |
| 673 | """ |
| 674 | if not count: |
| 675 | return start if start is not None else 1 |
Ethan Furman | c16595e | 2016-09-10 23:36:59 -0700 | [diff] [blame] | 676 | for last_value in reversed(last_values): |
| 677 | try: |
| 678 | high_bit = _high_bit(last_value) |
| 679 | break |
Ethan Furman | 3515dcc | 2016-09-18 13:15:41 -0700 | [diff] [blame] | 680 | except Exception: |
Ethan Furman | c16595e | 2016-09-10 23:36:59 -0700 | [diff] [blame] | 681 | raise TypeError('Invalid Flag value: %r' % last_value) from None |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 682 | return 2 ** (high_bit+1) |
| 683 | |
| 684 | @classmethod |
| 685 | def _missing_(cls, value): |
| 686 | original_value = value |
| 687 | if value < 0: |
| 688 | value = ~value |
| 689 | possible_member = cls._create_pseudo_member_(value) |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 690 | if original_value < 0: |
| 691 | possible_member = ~possible_member |
| 692 | return possible_member |
| 693 | |
| 694 | @classmethod |
| 695 | def _create_pseudo_member_(cls, value): |
Ethan Furman | 3515dcc | 2016-09-18 13:15:41 -0700 | [diff] [blame] | 696 | """ |
| 697 | Create a composite member iff value contains only members. |
| 698 | """ |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 699 | pseudo_member = cls._value2member_map_.get(value, None) |
| 700 | if pseudo_member is None: |
Ethan Furman | 3515dcc | 2016-09-18 13:15:41 -0700 | [diff] [blame] | 701 | # verify all bits are accounted for |
| 702 | _, extra_flags = _decompose(cls, value) |
| 703 | if extra_flags: |
| 704 | raise ValueError("%r is not a valid %s" % (value, cls.__name__)) |
| 705 | # construct a singleton enum pseudo-member |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 706 | pseudo_member = object.__new__(cls) |
| 707 | pseudo_member._name_ = None |
| 708 | pseudo_member._value_ = value |
Ethan Furman | 28cf663 | 2017-01-24 12:12:06 -0800 | [diff] [blame] | 709 | # use setdefault in case another thread already created a composite |
| 710 | # with this value |
| 711 | pseudo_member = cls._value2member_map_.setdefault(value, pseudo_member) |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 712 | return pseudo_member |
| 713 | |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 714 | def __contains__(self, other): |
| 715 | if not isinstance(other, self.__class__): |
| 716 | return NotImplemented |
| 717 | return other._value_ & self._value_ == other._value_ |
| 718 | |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 719 | def __repr__(self): |
| 720 | cls = self.__class__ |
| 721 | if self._name_ is not None: |
| 722 | return '<%s.%s: %r>' % (cls.__name__, self._name_, self._value_) |
Ethan Furman | 3515dcc | 2016-09-18 13:15:41 -0700 | [diff] [blame] | 723 | members, uncovered = _decompose(cls, self._value_) |
Ethan Furman | 27682d2 | 2016-09-04 11:39:01 -0700 | [diff] [blame] | 724 | return '<%s.%s: %r>' % ( |
| 725 | cls.__name__, |
| 726 | '|'.join([str(m._name_ or m._value_) for m in members]), |
| 727 | self._value_, |
| 728 | ) |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 729 | |
| 730 | def __str__(self): |
| 731 | cls = self.__class__ |
| 732 | if self._name_ is not None: |
| 733 | return '%s.%s' % (cls.__name__, self._name_) |
Ethan Furman | 3515dcc | 2016-09-18 13:15:41 -0700 | [diff] [blame] | 734 | members, uncovered = _decompose(cls, self._value_) |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 735 | if len(members) == 1 and members[0]._name_ is None: |
| 736 | return '%s.%r' % (cls.__name__, members[0]._value_) |
| 737 | else: |
| 738 | return '%s.%s' % ( |
| 739 | cls.__name__, |
| 740 | '|'.join([str(m._name_ or m._value_) for m in members]), |
| 741 | ) |
| 742 | |
Ethan Furman | 25d94bb | 2016-09-02 16:32:32 -0700 | [diff] [blame] | 743 | def __bool__(self): |
| 744 | return bool(self._value_) |
| 745 | |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 746 | def __or__(self, other): |
| 747 | if not isinstance(other, self.__class__): |
| 748 | return NotImplemented |
| 749 | return self.__class__(self._value_ | other._value_) |
| 750 | |
| 751 | def __and__(self, other): |
| 752 | if not isinstance(other, self.__class__): |
| 753 | return NotImplemented |
| 754 | return self.__class__(self._value_ & other._value_) |
| 755 | |
| 756 | def __xor__(self, other): |
| 757 | if not isinstance(other, self.__class__): |
| 758 | return NotImplemented |
| 759 | return self.__class__(self._value_ ^ other._value_) |
| 760 | |
| 761 | def __invert__(self): |
Ethan Furman | 3515dcc | 2016-09-18 13:15:41 -0700 | [diff] [blame] | 762 | members, uncovered = _decompose(self.__class__, self._value_) |
Serhiy Storchaka | 8110837 | 2017-09-26 00:55:55 +0300 | [diff] [blame] | 763 | inverted = self.__class__(0) |
| 764 | for m in self.__class__: |
| 765 | if m not in members and not (m._value_ & self._value_): |
| 766 | inverted = inverted | m |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 767 | return self.__class__(inverted) |
| 768 | |
| 769 | |
Ethan Furman | 65a5a47 | 2016-09-01 23:55:19 -0700 | [diff] [blame] | 770 | class IntFlag(int, Flag): |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 771 | """Support for integer-based Flags""" |
| 772 | |
| 773 | @classmethod |
Ethan Furman | 3515dcc | 2016-09-18 13:15:41 -0700 | [diff] [blame] | 774 | def _missing_(cls, value): |
| 775 | if not isinstance(value, int): |
| 776 | raise ValueError("%r is not a valid %s" % (value, cls.__name__)) |
| 777 | new_member = cls._create_pseudo_member_(value) |
| 778 | return new_member |
| 779 | |
| 780 | @classmethod |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 781 | def _create_pseudo_member_(cls, value): |
| 782 | pseudo_member = cls._value2member_map_.get(value, None) |
| 783 | if pseudo_member is None: |
Ethan Furman | 3515dcc | 2016-09-18 13:15:41 -0700 | [diff] [blame] | 784 | need_to_create = [value] |
| 785 | # get unaccounted for bits |
| 786 | _, extra_flags = _decompose(cls, value) |
| 787 | # timer = 10 |
| 788 | while extra_flags: |
| 789 | # timer -= 1 |
| 790 | bit = _high_bit(extra_flags) |
| 791 | flag_value = 2 ** bit |
| 792 | if (flag_value not in cls._value2member_map_ and |
| 793 | flag_value not in need_to_create |
| 794 | ): |
| 795 | need_to_create.append(flag_value) |
| 796 | if extra_flags == -flag_value: |
| 797 | extra_flags = 0 |
| 798 | else: |
| 799 | extra_flags ^= flag_value |
| 800 | for value in reversed(need_to_create): |
| 801 | # construct singleton pseudo-members |
| 802 | pseudo_member = int.__new__(cls, value) |
| 803 | pseudo_member._name_ = None |
| 804 | pseudo_member._value_ = value |
Ethan Furman | 28cf663 | 2017-01-24 12:12:06 -0800 | [diff] [blame] | 805 | # use setdefault in case another thread already created a composite |
| 806 | # with this value |
| 807 | pseudo_member = cls._value2member_map_.setdefault(value, pseudo_member) |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 808 | return pseudo_member |
| 809 | |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 810 | def __or__(self, other): |
| 811 | if not isinstance(other, (self.__class__, int)): |
| 812 | return NotImplemented |
Ethan Furman | 3515dcc | 2016-09-18 13:15:41 -0700 | [diff] [blame] | 813 | result = self.__class__(self._value_ | self.__class__(other)._value_) |
| 814 | return result |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 815 | |
| 816 | def __and__(self, other): |
| 817 | if not isinstance(other, (self.__class__, int)): |
| 818 | return NotImplemented |
| 819 | return self.__class__(self._value_ & self.__class__(other)._value_) |
| 820 | |
| 821 | def __xor__(self, other): |
| 822 | if not isinstance(other, (self.__class__, int)): |
| 823 | return NotImplemented |
| 824 | return self.__class__(self._value_ ^ self.__class__(other)._value_) |
| 825 | |
| 826 | __ror__ = __or__ |
| 827 | __rand__ = __and__ |
| 828 | __rxor__ = __xor__ |
| 829 | |
| 830 | def __invert__(self): |
Ethan Furman | 3515dcc | 2016-09-18 13:15:41 -0700 | [diff] [blame] | 831 | result = self.__class__(~self._value_) |
| 832 | return result |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 833 | |
| 834 | |
| 835 | def _high_bit(value): |
Ethan Furman | 0443953 | 2016-09-02 15:50:21 -0700 | [diff] [blame] | 836 | """returns index of highest bit, or -1 if value is zero or negative""" |
Ethan Furman | 3515dcc | 2016-09-18 13:15:41 -0700 | [diff] [blame] | 837 | return value.bit_length() - 1 |
Ethan Furman | ee47e5c | 2016-08-31 00:12:15 -0700 | [diff] [blame] | 838 | |
Ethan Furman | f24bb35 | 2013-07-18 17:05:39 -0700 | [diff] [blame] | 839 | def unique(enumeration): |
| 840 | """Class decorator for enumerations ensuring unique member values.""" |
| 841 | duplicates = [] |
| 842 | for name, member in enumeration.__members__.items(): |
| 843 | if name != member.name: |
| 844 | duplicates.append((name, member.name)) |
| 845 | if duplicates: |
| 846 | alias_details = ', '.join( |
| 847 | ["%s -> %s" % (alias, name) for (alias, name) in duplicates]) |
| 848 | raise ValueError('duplicate values found in %r: %s' % |
| 849 | (enumeration, alias_details)) |
| 850 | return enumeration |
Ethan Furman | 3515dcc | 2016-09-18 13:15:41 -0700 | [diff] [blame] | 851 | |
| 852 | def _decompose(flag, value): |
| 853 | """Extract all members from the value.""" |
| 854 | # _decompose is only called if the value is not named |
| 855 | not_covered = value |
| 856 | negative = value < 0 |
Ethan Furman | 28cf663 | 2017-01-24 12:12:06 -0800 | [diff] [blame] | 857 | # issue29167: wrap accesses to _value2member_map_ in a list to avoid race |
Ville Skyttä | 49b2734 | 2017-08-03 09:00:59 +0300 | [diff] [blame] | 858 | # conditions between iterating over it and having more pseudo- |
Ethan Furman | 28cf663 | 2017-01-24 12:12:06 -0800 | [diff] [blame] | 859 | # members added to it |
Ethan Furman | 3515dcc | 2016-09-18 13:15:41 -0700 | [diff] [blame] | 860 | if negative: |
| 861 | # only check for named flags |
| 862 | flags_to_check = [ |
| 863 | (m, v) |
Ethan Furman | 28cf663 | 2017-01-24 12:12:06 -0800 | [diff] [blame] | 864 | for v, m in list(flag._value2member_map_.items()) |
Ethan Furman | 3515dcc | 2016-09-18 13:15:41 -0700 | [diff] [blame] | 865 | if m.name is not None |
| 866 | ] |
| 867 | else: |
| 868 | # check for named flags and powers-of-two flags |
| 869 | flags_to_check = [ |
| 870 | (m, v) |
Ethan Furman | 28cf663 | 2017-01-24 12:12:06 -0800 | [diff] [blame] | 871 | for v, m in list(flag._value2member_map_.items()) |
Ethan Furman | 3515dcc | 2016-09-18 13:15:41 -0700 | [diff] [blame] | 872 | if m.name is not None or _power_of_two(v) |
| 873 | ] |
| 874 | members = [] |
| 875 | for member, member_value in flags_to_check: |
| 876 | if member_value and member_value & value == member_value: |
| 877 | members.append(member) |
| 878 | not_covered &= ~member_value |
| 879 | if not members and value in flag._value2member_map_: |
| 880 | members.append(flag._value2member_map_[value]) |
| 881 | members.sort(key=lambda m: m._value_, reverse=True) |
| 882 | if len(members) > 1 and members[0].value == value: |
| 883 | # we have the breakdown, don't need the value member itself |
| 884 | members.pop(0) |
| 885 | return members, not_covered |
| 886 | |
| 887 | def _power_of_two(value): |
| 888 | if value < 1: |
| 889 | return False |
| 890 | return value == 2 ** _high_bit(value) |