Consider:
class Item:
def __init__(self, a, b):
self.a = a
self.b = b
class Items:
GREEN = Item('a', 'b')
BLUE = Item('c', 'd')
Is there a way to adapt the ideas for simple enums to this case? (see this question) Ideally, as in Java, I would like to cram it all into one class.
Java model:
enum EnumWithAttrs {
GREEN("a", "b"),
BLUE("c", "d");
EnumWithAttrs(String a, String b) {
this.a = a;
this.b = b;
}
private String a;
private String b;
/* accessors and other java noise */
}
Python 3.4 has a new Enum data type (which has been backported as enum34
and enhanced as aenum
1). Both enum34
and aenum
2 easily support your use case:
aenum
(Python 2/3)
import aenum
class EnumWithAttrs(aenum.AutoNumberEnum):
_init_ = 'a b'
GREEN = 'a', 'b'
BLUE = 'c', 'd'
enum34
(Python 2/3) or standard library enum
(Python 3.4+)
import enum
class EnumWithAttrs(enum.Enum):
def __new__(cls, *args, **kwds):
value = len(cls.__members__) + 1
obj = object.__new__(cls)
obj._value_ = value
return obj
def __init__(self, a, b):
self.a = a
self.b = b
GREEN = 'a', 'b'
BLUE = 'c', 'd'
And in use:
>>> EnumWithAttrs.BLUE
<EnumWithAttrs.BLUE: 1>
>>> EnumWithAttrs.BLUE.a
'c'
1 Disclosure: I am the author of the Python stdlib Enum
, the enum34
backport, and the Advanced Enumeration (aenum
) library.
2 aenum
also supports NamedConstants
and metaclass-based NamedTuples
.