Python __slots__ (making And Using)

I don't really get making a class and using __slots__ can someone make it clearer? For example, I'm trying to make two classes, one is empty the other isn't. I got this so far: cl

Solution 1:

You then have to initialize your class in a traditional way. It will work like this :

classEmpty:
    __slots__ =()

defmkEmpty():
    return Empty()

classNonEmpty():
    __slots__ = ('one', 'two')

    def__init__(self, one, two):
        self.one = one
        self.two = two

defmkNonEmpty(one, two):
    return NonEmpty(one, two)

Actually, the constructor functions are non-necessary and non pythonic. You can, and should use the class constructor directly, like so :

ne = NonEmpty(1, 2)

You can also use an empty constructor and set the slots directly in your application, if what you need is some kind of record

class NonEmpty():
    __slots__ = ('one', 'two')

n = NonEmpty()
n.one = 12
n.two = 15

You need to understand that slots are only necessary for performance/memory reasons. You don't need to use them, and probably shouldn't use them, except if you know that you are memory constrained. This only should be after actually stumbling into a problem though.

Solution 2:

Maybe the docs will help? Honestly, it doesn't sound like you're at a level where you need to be worrying about __slots__.