How to refer to the class from within it (like a recursive function)

Question

For a recursive function we can do:

def f(i):   if i<0: return   print i   f(i-1)  f(10) 

However is there a way to do the following thing?

class A:   # do something   some_func(A)   # ... 

Answer 1

If I understand your question correctly, you should be able to reference class A within class A by putting the type annotation in quotes. This is called forward reference.

class A:   # do something   def some_func(self, a: 'A')   # ... 

See ref below

1. https://github.com/python/mypy/issues/3661
2. https://www.youtube.com/watch?v=AJsrxBkV3kc

Answer 2

In Python you cannot reference the class in the class body, although in languages like Ruby you can do it.

In Python instead you can use a class decorator but that will be called once the class has initialized. Another way could be to use metaclass but it depends on what you are trying to achieve.