print something when access to an attribute

Question

I am trying to print something when I am accessing to an attribute of a class by using __getattribute__ The big problem here is recursion and the fact I am overriding getattribute method.

I am afraid I have to use metaclass to solve this problem. Anyway if you any answer of this problem.

Answer 1

__getattribute__ is used for all attribute access on your instance. That includes self.recursion in that method.

You rarely need to use __getattribute__. If you do actually have a proper use-case for it, avoid attribute access or use super(A, self).__getattribute__() to avoid infinite recursion problems.

For your usecase (printing something whenever an attribute is being accessed), do use super() still to return the original attribute:

class A(object):
    def meth(self):
        return "met"

    def __getattribute__(self, name):
        print "IN CLASS A"
        return super(A, self).__getattribute__(name)

Note that for super() to work you do need to use a new-style class, inheriting from object. If you are inheriting from something else, and that something else has a __getattribute__ method, it is already a new-style class.