>>>>> Steven D'Aprano <st...@removethis.cybersource.com.au> (SD) wrote:
>SD> Lorenzo Di Gregorio wrote: >>> Hi, >>> >>> I'm wondering what would be the preferred way to solve the following >>> forward reference problem: >SD> You don't actually explain what is the problem. Fortunately, I'm good at >SD> guessing, and I think I can guess what your problem is (see below): >>> --------------------------------------- >>> class BaseA(object): >>> def __init__(self): >>> return >>> >>> class DebugA(BaseA): >>> def __init__(self): >>> return >>> >>> # here I would have a prototype of class A which is the same as class >>> BaseA >>> >>> class B(object): >>> def __init__(self): >>> self.obj = A() >>> return >>> >>> if __name__ == "__main__": >>> # class A(BaseA): # Uncomment this for using BaseA objects >>> # pass >>> class A(DebugA): # Uncomment this for using DebugA objects >>> pass >>> --------------------------------------- >SD> Class A only gets defined if you run the module as a script. What you need >SD> is to unconditionally define class A, outside of the if __name__ block: >SD> class A(BaseA): >SD> pass >SD> # A.__base__ = DebugA ## Uncomment this line for debugging. >>>A.__base__ = DebugA TypeError: readonly attribute Make that: A.__bases__ = DebugA, >SD> -- >SD> Steven -- Piet van Oostrum <p...@cs.uu.nl> URL: http://pietvanoostrum.com [PGP 8DAE142BE17999C4] Private email: p...@vanoostrum.org -- http://mail.python.org/mailman/listinfo/python-list
