On 10/22/2019 03:13 PM, Steve Jorgensen wrote:
Ethan Furman wrote:
Experimenting is good! However, you'll want to either build your own metaclass
and/or prepared dict, or do some work on your __new__/__init__
methods for building enum members. Currently, you are reassigning _value_ in
__init__, which leaves some internal structures not matching the Enum.
--> class Food(ChoiceEnum):
... APPLE = ()
... ICED_TEA = ()
...
--> Food['APPLE']
<Food.APPLE: 'APPLE'>
--> Food.APPLE
<Food.APPLE: 'APPLE'>
--> Food('APPLE')
Traceback (most recent call last):
...
ValueError: 'APPLE' is not a valid Food
Thanks for that info.
Per the example in
https://docs.python.org/3/library/enum.html#when-to-use-new-vs-init, it looks
like I can properly set the `_value_` property in the `__new__` method of the
`Enum` subclass without needing to subclass `EnumMeta`. Am I understanding that
correctly?
Yes, you are. The fun part for you is that the value can sometimes be the
name, and the name is not passed into `__new__`.
The name /is/ passed into `_generate_next_value_`, but if any value is supplied
then `_generate_next_value_` isn't called.
I haven't had enough space cycles to either find a solution or rule any out,
but I know the limitations above are baked into EnumMeta and _EnumDict, so if
you rolled your own you could simply not put them in.
--
~Ethan~
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