具有重复值的Python枚举 [英] Python Enums with duplicate values

问题描述

我无法使用其中某些属性具有相同值的Enum。我认为Enums是python的新手，所以我找不到关于此问题的其他参考。无论如何，假设我有以下

I'm having trouble working with an Enum where some attributes have the same value. I think Enums are so new to python that I can't find any other reference to this issue. In any case, let's say I have the following

class CardNumber(Enum):
    ACE      = 11
    TWO      = 2
    THREE    = 3
    FOUR     = 4
    FIVE     = 5
    SIX      = 6
    SEVEN    = 7
    EIGHT    = 8
    NINE     = 9
    TEN      = 10
    JACK     = 10
    QUEEN    = 10
    KING     = 10

很显然，这些是黑色插孔中的卡号及其对应的值。十个通王具有相同的价值。但是，如果我执行 print（CardNumber.QUEEN）之类的操作，我会得到< CardNumber.TEN：10> 。更重要的是，如果我遍历这些，它只会遍历唯一值。

Clearly these are the card numbers and their corresponding values in black jack. The ten through king have the same value. But if I do something like print(CardNumber.QUEEN), I get back <CardNumber.TEN: 10>. What's more, if I iterate over these, it simply iterates over unique values.

>>> for elem in CardNumber:
...     print(elem)
CardNumber.ACE
CardNumber.TWO
CardNumber.THREE
CardNumber.FOUR
CardNumber.FIVE
CardNumber.SIX
CardNumber.SEVEN
CardNumber.EIGHT
CardNumber.NINE
CardNumber.TEN

如何解决这个问题？我希望CardNumber.QUEEN和CardNumber.TEN是唯一的，并且都出现在任何迭代中。我唯一能想到的就是为每个属性赋予第二个值，该值将充当不同的id，但这似乎是不合逻辑的。

How can I get around this issue? I want CardNumber.QUEEN and CardNumber.TEN to be unique, and both appear in any iteration. The only thing I could think of was to give each attribute a second value which would act as a distinct id, but that seems unpythonic.

推荐答案

是的，具有重复值的标签将变成第一个此类标签的别名。

Yes, labels with duplicate values are turned into aliases for the first such label.

您可以枚举 __ members __ 属性，它是一个包含别名的有序词典：

You can enumerate over the __members__ attribute, it is an ordered dictionary with the aliases included:

>>> for name, value in CardNumber.__members__.items():
...     print(name, value)
... 
ACE CardNumber.ACE
TWO CardNumber.TWO
THREE CardNumber.THREE
FOUR CardNumber.FOUR
FIVE CardNumber.FIVE
SIX CardNumber.SIX
SEVEN CardNumber.SEVEN
EIGHT CardNumber.EIGHT
NINE CardNumber.NINE
TEN CardNumber.TEN
JACK CardNumber.TEN
QUEEN CardNumber.TEN
KING CardNumber.TEN

但是，如果必须具有唯一的标签和值对（而不是别名），则请 enum.Enum 是错误的方法；

However, if you must have label-and-value pairs that are unique (and not aliases), then enum.Enum is the wrong approach here; it doesn't match the usecases for a card game.

在这种情况下，最好使用字典（考虑使用集合。 OrderedDict（）（如果订单也很重要）。

In that case it'll be better to use a dictionary (consider using collections.OrderedDict() if order is important too).

这篇关于具有重复值的Python枚举的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！