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from __future__ import annotations
import sys
from enum import (
EnumMeta,
IntEnum,
)
from types import MappingProxyType
from typing import (
TYPE_CHECKING,
Any,
Dict,
Optional,
Tuple,
)
if TYPE_CHECKING:
from collections.abc import (
Generator,
Mapping,
)
from typing_extensions import (
Never,
Self,
)
def _is_descriptor(obj: object) -> bool:
return (
hasattr(obj, "__get__") or hasattr(obj, "__set__") or hasattr(obj, "__delete__")
)
class EnumType(EnumMeta if TYPE_CHECKING else type):
_value_map_: Mapping[int, Enum]
_member_map_: Mapping[str, Enum]
def __new__(
mcs, name: str, bases: Tuple[type, ...], namespace: Dict[str, Any]
) -> Self:
value_map = {}
member_map = {}
new_mcs = type(
f"{name}Type",
tuple(
dict.fromkeys(
[base.__class__ for base in bases if base.__class__ is not type]
+ [EnumType, type]
)
), # reorder the bases so EnumType and type are last to avoid conflicts
{"_value_map_": value_map, "_member_map_": member_map},
)
members = {
name: value
for name, value in namespace.items()
if not _is_descriptor(value) and not name.startswith("__")
}
cls = type.__new__(
new_mcs,
name,
bases,
{key: value for key, value in namespace.items() if key not in members},
)
# this allows us to disallow member access from other members as
# members become proper class variables
for name, value in members.items():
member = value_map.get(value)
if member is None:
member = cls.__new__(cls, name=name, value=value) # type: ignore
value_map[value] = member
member_map[name] = member
type.__setattr__(new_mcs, name, member)
return cls
if not TYPE_CHECKING:
def __call__(cls, value: int) -> Enum:
try:
return cls._value_map_[value]
except (KeyError, TypeError):
raise ValueError(f"{value!r} is not a valid {cls.__name__}") from None
def __iter__(cls) -> Generator[Enum, None, None]:
yield from cls._member_map_.values()
def __reversed__(cls) -> Generator[Enum, None, None]:
yield from reversed(cls._member_map_.values())
def __getitem__(cls, key: str) -> Enum:
return cls._member_map_[key]
@property
def __members__(cls) -> MappingProxyType[str, Enum]:
return MappingProxyType(cls._member_map_)
def __repr__(cls) -> str:
return f"<enum {cls.__name__!r}>"
def __len__(cls) -> int:
return len(cls._member_map_)
def __setattr__(cls, name: str, value: Any) -> Never:
raise AttributeError(f"{cls.__name__}: cannot reassign Enum members.")
def __delattr__(cls, name: str) -> Never:
raise AttributeError(f"{cls.__name__}: cannot delete Enum members.")
def __contains__(cls, member: object) -> bool:
return isinstance(member, cls) and member.name in cls._member_map_
class Enum(IntEnum if TYPE_CHECKING else int, metaclass=EnumType):
"""
The base class for protobuf enumerations, all generated enumerations will
inherit from this. Emulates `enum.IntEnum`.
"""
name: Optional[str]
value: int
if not TYPE_CHECKING:
def __new__(cls, *, name: Optional[str], value: int) -> Self:
self = super().__new__(cls, value)
super().__setattr__(self, "name", name)
super().__setattr__(self, "value", value)
return self
def __str__(self) -> str:
return self.name or "None"
def __repr__(self) -> str:
return f"{self.__class__.__name__}.{self.name}"
def __setattr__(self, key: str, value: Any) -> Never:
raise AttributeError(
f"{self.__class__.__name__} Cannot reassign a member's attributes."
)
def __delattr__(self, item: Any) -> Never:
raise AttributeError(
f"{self.__class__.__name__} Cannot delete a member's attributes."
)
def __copy__(self) -> Self:
return self
def __deepcopy__(self, memo: Any) -> Self:
return self
@classmethod
def try_value(cls, value: int = 0) -> Self:
"""Return the value which corresponds to the value.
Parameters
-----------
value: :class:`int`
The value of the enum member to get.
Returns
-------
:class:`Enum`
The corresponding member or a new instance of the enum if
``value`` isn't actually a member.
"""
try:
return cls._value_map_[value]
except (KeyError, TypeError):
return cls.__new__(cls, name=None, value=value)
@classmethod
def from_string(cls, name: str) -> Self:
"""Return the value which corresponds to the string name.
Parameters
-----------
name: :class:`str`
The name of the enum member to get.
Raises
-------
:exc:`ValueError`
The member was not found in the Enum.
"""
try:
return cls._member_map_[name]
except KeyError as e:
raise ValueError(f"Unknown value {name} for enum {cls.__name__}") from e
|
