An attempt to allow a Python StrEnum member to be marked as deprecated

enum_utilities.py

from enum import StrEnum
import warnings


class StrEnumWithDeprecationSupport(StrEnum):
    """String-based Enum with support for deprecation warnings."""

    def __new__(cls, *values):
        """Values must already be of type `str`
        
        We are overriding the `__new__` method of the standard library's `StrEnum` because it
        only supports members whose values map to the `str` arguments (because they're passed
        to `str` here:
        https://github.com/python/cpython/blob/e33b6fccd3969dc2351f6a64d7b0362c36c2be96/Lib/enum.py#L1296).
        
        This "works", in that it emits a DeprecationWarning, but it emits it at the time of enum
        class creation, and not at time of member reference (which is what I actually want).
        """
        if len(values) > 2:
            raise TypeError("too many arguments for str(): %r" % (values,))
        if len(values) == 1:
            if not isinstance(values[0], str):
                raise TypeError("%r is not a string" % (values[0],))
        if len(values) == 2:
            if not isinstance(values[1], dict):
                raise TypeError("deprecation object must be a dict")
            if "__deprecated__" not in values[1]:
                raise TypeError("deprecation object must have a __deprecated__ key")
            if not isinstance(values[1]["__deprecated__"], str):
                raise TypeError("deprecation object must have a string value for the __deprecated__ key")
            warnings.warn(values[1]["__deprecated__"], DeprecationWarning, 2)
        # this is gross - we trust that our use cases don't need the other args that `str` supports,
        # so we only pass the first value to `str` here, and we understand the second element in the
        # member value to be a "deprecation configuration object", or something.
        value = str(values[0])
        member = str.__new__(cls, value)
        member._value_ = value
        if len(values) == 2:
            member.__deprecated__ = values[1]["__deprecated__"]
        return member

enums.py

from enum import unique

from .enum_utilities import StrEnumWithDeprecationSupport

@unique
class Timezone(StrEnumWithDeprecationSupport):
    US_CENTRAL = "US/Central", {"__deprecated__": "US_CENTRAL is deprecated. Use IANA standard AMERICA_CHICAGO instead."}
    AMERICA_CHICAGO = "America/Chicago"