On 7 May 2013 14:54, Ethan Furman <et...@stoneleaf.us> wrote:
> On 05/06/2013 07:58 PM, Tim Delaney wrote:
>
>>
>> Considering that doesn't actually work with the reference implementation
>> (AutoNumber.__new__ is never called) ... no.
>>
>
> Two points:
>
> 1) Did you grab the latest code? That exact implementation passes in
> the tests.
>
D'oh! I had my default path being my forked repo ... so didn't see the
changes. BTW I can't see how that exact implementation passes ... not
enough parameters declared in AutoNumber.__new__ ...
> 2) You can write your __new__ however you want -- use ... ! ;)
class AutoNumber(Enum):
def __new__(cls, value):
if value is Ellipsis:
try:
value = cls._auto_number
except AttributeError:
value = cls._auto_number = 0
else:
cls._auto_number = int(value)
obj = object.__new__(cls)
obj._value = value
cls._auto_number += 1
return obj
def __int__(self):
return self._value
class Color(AutoNumber):
red = ...
green = 3
blue = ...
print(repr(Color.red))
print(repr(Color.green))
print(repr(Color.blue))
---------- Run Python3 ----------
<Color.red: 0>
<Color.green: 3>
<Color.blue: 4>
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'
I would probably also suggest 2 changes:
1. Set enum_item._name before calling enum_item.__init__.
2. Don't pass any arguments to enum_item.__init__ - the value should be set
in enum_item.__new__.
Tim Delaney
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