bpo-37062: Enum: add extended AutoNumber example (GH-22349) (GH-22369)
(cherry picked from commit 62e40d8450
)
Co-authored-by: Ethan Furman <ethan@stoneleaf.us>
This commit is contained in:
parent
2466a7ae6b
commit
5acc1b5f0b
|
@ -888,6 +888,32 @@ Using an auto-numbering :meth:`__new__` would look like::
|
|||
>>> Color.GREEN.value
|
||||
2
|
||||
|
||||
To make a more general purpose ``AutoNumber``, add ``*args`` to the signature::
|
||||
|
||||
>>> class AutoNumber(NoValue):
|
||||
... def __new__(cls, *args): # this is the only change from above
|
||||
... value = len(cls.__members__) + 1
|
||||
... obj = object.__new__(cls)
|
||||
... obj._value_ = value
|
||||
... return obj
|
||||
...
|
||||
|
||||
Then when you inherit from ``AutoNumber`` you can write your own ``__init__``
|
||||
to handle any extra arguments::
|
||||
|
||||
>>> class Swatch(AutoNumber):
|
||||
... def __init__(self, pantone='unknown'):
|
||||
... self.pantone = pantone
|
||||
... AUBURN = '3497'
|
||||
... SEA_GREEN = '1246'
|
||||
... BLEACHED_CORAL = () # New color, no Pantone code yet!
|
||||
...
|
||||
>>> Swatch.SEA_GREEN
|
||||
<Swatch.SEA_GREEN: 2>
|
||||
>>> Swatch.SEA_GREEN.pantone
|
||||
'1246'
|
||||
>>> Swatch.BLEACHED_CORAL.pantone
|
||||
'unknown'
|
||||
|
||||
.. note::
|
||||
|
||||
|
|
Loading…
Reference in New Issue