python: how to refer to the class from within it ( like the 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 thin

Answer 1

If you want to do just a little hacky thing do

class A(object):
    ...
some_func(A)

If you want to do something more sophisticated you can use a metaclass. A metaclass is responsible for manipulating the class object before it gets fully created. A template would be:

class AType(type):
    def __new__(meta, name, bases, dct):
        cls = super(AType, meta).__new__(meta, name, bases, dct)
        some_func(cls)
        return cls

class A(object):
    __metaclass__ = AType
    ...

type is the default metaclass. Instances of metaclasses are classes so __new__ returns a modified instance of (in this case) A.

For more on metaclasses, see http://docs.python.org/reference/datamodel.html#customizing-class-creation.