Does Python have class prototypes (or forward declarations)?

Question

I have a series of Python classes in a file. Some classes reference others.

My code is something like this:

class A():
    pass

class B():
    c = C         


        

Answer 1

A decade after the question is asked, I have encountered the same problem. While people suggest that the referencing should be done inside the init method, there are times when you need to access the data as a "class attribute" before the class is actually instantiated. For that reason, I have come up with a simple solution using a descriptor.

class A():
    pass

class B():
    class D(object):
        def __init__(self):
            self.c = None
        def __get__(self, instance, owner):
            if not self.c:
                self.c = C()
            return self.c
    c = D()

class C():
    pass

>>> B.c
>>> <__main__.C object at 0x10cc385f8>