Checking for member existence in Python

Question

I regularly want to check if an object has a member or not. An example is the creation of a singleton in a function. For that purpose, you can use hasattr like

Answer 1

A little off-topic in the way of using it. Singletons are overrated, and a "shared-state" method is as effective, and mostly, very clean in python, for example:

class Borg:
    __shared_state = {}
    def __init__(self):
        self.__dict__ = self.__shared_state
    # and whatever else you want in your class -- that's all!

Now every time you do:

obj = Borg()

it will have the same information, or, be somewhat the same instance.