Question

I would like to do something along the lines of…

class MyClassA(object):
    an_attr = AnotherClassB(do_something=MyClassA.hello)

    @classmethod
    def hello(cls):
        return "Hello"

however it will tell me MyClassA is not defined when I try to run it.

• an_attr must be a class attribute
• I can’t alter AnotherClassB
• I would prefer if hello() remained a classmethod

Any ideas?

Answer 1

You just have to get the order right, so it’s defined before you use it:

class MyClassA(object):
    @classmethod
    def hello(cls):
        return "Hello"

    an_attr = AnotherClassB(do_something=hello)

Note that, because it’s in the namespace when we’re creating the class, we just refer to hello, not to MyClassA.hello.

EDIT: Sorry, this doesn’t actually do what I thought it did. It creates the class without an error, but AnotherClassB only gets a reference to the unbound classmethod, which can’t be called.