[issue34909] StrEnum subclasses cannot be created

[Ethan Furman]

New submission from Ethan Furman <ethan at stoneleaf.us>:

from enum import Enum, unique

class StrEnum(str, Enum):
    def __new__(cls, *args, **kwargs):
        for a in args:
            if not isinstance(a, str):
                raise TypeError("Enumeration '%s' (%s) is not"
                                " a string" % (a, type(a).__name__))
        return super(StrEnum, cls).__new__(cls, *args, **kwargs)

@unique
class Decision(StrEnum):
    """Decision results/strategy enumeration."""
    REVERT = "REVERT"
    REVERT_ALL = "REVERT_ALL"
    RETRY = "RETRY"

---

Traceback (most recent call last):
  File "test", line 14, in <module>
    class Decision(StrEnum):
  File ".../cpython/Lib/enum.py", line 222, in __new__
    enum_member._value_ = member_type(*args)
  File ".../cpython/Lib/enum.py", line 309, in __call__
    return cls.__new__(cls, value)
  File ".../cpython/Lib/enum.py", line 545, in __new__
    return cls._missing_(value)
  File ".../cpython/Lib/enum.py", line 558, in _missing_
    raise ValueError("%r is not a valid %s" % (value, cls.__name__))
ValueError: 'REVERT' is not a valid StrEnum

----------
assignee: ethan.furman
keywords: 3.7regression
messages: 327182
nosy: ethan.furman, ned.deily
priority: release blocker
severity: normal
stage: test needed
status: open
title: StrEnum subclasses cannot be created
versions: Python 3.7

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue34909>
_______________________________________