Python Module to mark enum members as deprecated

enum_deprecation.py

from enum import Enum, EnumMeta, auto
import warnings


class deprecated:
    """object to mark an enum member as deprecated

    This marker works much like the `enum.auto()`.
    
    At the moment only `Enum`s based on `object` work,
    e.g. `IntEnum` doesn't work.
    """
    value = object()

    def __init__(self, deprecation_msg_tpl=None):
        if deprecation_msg_tpl is None:
            deprecation_msg_tpl = (
                "The enum member {attr} is deprecated "
                "and will be removed in the future"
            )
        self._deprecation_msg_tpl = deprecation_msg_tpl

    def __repr__(self):
        return self._deprecation_msg_tpl


class allow_deprecation(EnumMeta):
    """Metaclass to properly handle the access to `deprecated` enum members"""
    def __getattribute__(cls, name):
        attr = type.__getattribute__(cls, name)
        if hasattr(attr, "value") and isinstance(attr.value, deprecated):
            warnings.warn(
                repr(attr).format(attr=attr.name),
                DeprecationWarning, stacklevel=2
            )
        return attr


class MyEnum(Enum, metaclass=allow_deprecation):
    FOO = auto()
    BAR = deprecated()
    MEH = auto()
    BAR2 = deprecated("The enum member {attr} will be removed tomorrow")


if __name__ == "__main__":
    warnings.simplefilter("default")

    print("FOO", MyEnum.FOO, MyEnum.FOO.value)
    print("BAR", MyEnum.BAR, MyEnum.BAR.value)
    print("MEH", MyEnum.MEH, MyEnum.MEH.value)
    print("BAR", MyEnum.BAR, MyEnum.BAR.value)
    print("BAR2", MyEnum.BAR2, MyEnum.BAR2.value)