Fast way to initialize class variables in Python

Question

I would like to initialize an instance and let both args and kwargs become class variables.

class Example():
    def __init__(
        self,
        a: str,
        b: bool,
        c: int,
        d="str",
        e=True,
        f=123,
    ):
        class_member = dict(locals())
        del class_member["self"]
        self.set_property(class_member)

    @classmethod
    def set_property(cls, kwargs):
        for key, value in kwargs.items():
            setattr(cls, key, value)

a = Example("test", True, 1, d="test", e=False, f=456)
print(Example.d)  # test

I have searched a lot and get the above result.

Is there any other cleaner way to deal with that? Thanks!

--Edit--

Thanks for all answers. My simplified version:

class Example():
    def __init__(
        self,
        a: str,
        b: bool,
        c: int,
        d="str",
        e=True,
        f=123,
    ):
        class_member = dict(locals())
        del class_member["self"]
        for key, value in class_member.items():
            setattr(Example, key, value)

a = Example("test", True, 1, d="test", e=False, f=456)
print(Example.d)  # test

I had thought about using **kwarg previously, but I still need to assign default value for kwargs. So this is my final solution.

It looks as good as it'll get, really. It's just that this is inherently messy; classes are intended to hold stuff common to all instances, not depend on the latest one. — BatWannaBe
– BatWannaBe, Commented Sep 22, 2021 at 9:07
@yedpodtrzitko I need to import Example class in other file (module) to access the class variable of Example after a is instanced. — Chuck Liu
– Chuck Liu, Commented Sep 22, 2021 at 9:47
That's… still not very clear, and sounds potentially extremely yucky as far as OOP and sane program structure is concerned. — deceze
– deceze ♦, Commented Sep 22, 2021 at 9:48
I have tried my best to make it OOP. The other classes need Example.d, Example.e and Example.f. Maybe there is other method to pass these variables. — Chuck Liu
– Chuck Liu, Commented Sep 22, 2021 at 9:50

Maurice Meyer · Accepted Answer · 2021-09-22 09:08:40Z

4

You could use setattr and kwargs only:

class Example:
    def __init__(self, **kwargs):
        for k, v in kwargs.items():
            setattr(Example, k, v)


a = Example(a="test", b=True, c=1, d="test", e=False, f=456)
print(Example.d)  # test

answered Sep 22, 2021 at 9:08

Maurice Meyer

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