EnumMeta implements its own __getitem__ function which doesn't respect
__class_getitem__. Now that __class_getitem__ exists, this behavior feels
unintuitive. For instance
```
class Directions(enum.Enum):
LEFT = "LEFT"
RIGHT = "RIGHT"
def __class_getitem__(cls, name):
return super().__class_getitem__(name.upper())
# fails with KeyError -- __class_getitem__ never called
assert Directions["left"] == Directions["LEFT"] == Directions.LEFT
```
doesn't work, and the only way to implement this behavior is something like
```
class MyEnumMeta(enum.EnumMeta):
def __getitem__(cls, name):
return cls.__class_getitem__(name)
class MyEnum(enum.Enum, metaclass=MyEnumMeta):
def __class_getitem__(cls, name):
return cls._member_map_[name]
class Directions(MyEnum): ...
```
there might be some compatibility issues with code written between 3.4 and
3.11, but not supporting __class_getitem__ feels like it violates the
principle of least surprise with the more recent data models.
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