Home Original page

[Python-Dev] PEP 435: initial values must be specified? Yes

Tim Delaney timothy.c.delaney at gmail.com
Tue May 7 07:18:41 CEST 2013 
On 7 May 2013 15:14, Tim Delaney <timothy.c.delaney at gmail.com> wrote:

> Unfortunately, if you subclass AutoNumber from IntEnum it breaks.
>
> ---------- Run Python3 ----------
> Traceback (most recent call last):
>   File "D:\home\repos\mercurial\ref435\ref435.py", line 346, in <module>
>     class Color(AutoNumber):
>   File "D:\home\repos\mercurial\ref435\ref435.py", line 184, in __new__
>     enum_item = __new__(enum_class, *args)
> TypeError: int() argument must be a string or a number, not 'ellipsis'
>

Or using your exact implementation, but subclassing AutoNumber from IntEnum:

    class AutoNumber(IntEnum):
        def __new__(cls):
            value = len(cls.__enum_info__) + 1
            obj = object.__new__(cls)
            obj._value = value
            return obj
        def __int__(self):
            return self._value
    class Color(AutoNumber):
        red = ()
        green = ()
        blue = ()

    print(repr(Color.red))

---------- Run Python3 ----------
<Color.red: ()>

Tim Delaney
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-dev/attachments/20130507/9503a9e5/attachment.html>
More information about the Python-Dev mailing list