How to override __str__ in nested class

Question

I've coded a parent class and a nested class. I've already overridden the parent class __str__ method and now I want to do the same on the nested class. But for some reason the __str__ method in the nested class is not getting called. And I can't see the instance variables in PyDev's autocompletion list when coding inside the nested class's str. Code:

class Parent(object):

    def __init__(self):
        self.parent_var = "Parent"

    def __str__(self):
        return self.parent_var


    class Nested(object):

        def __init__(self):
            #Works (of course, why shouldn't it?)
            self.children_var = "Child"

        def __str__(self):
            # This method never called!
            return self.children_var

Something odd is going on. Why can't the __str__ method just work like the __init__ did?

---

UPDATE:
You guys are right. The code was ok, but my str was trying to do this:

return "Some string" + some_integer

And apparently in Python you need to do str(some_integer) before concatenating stuff (this is actually lame).

Answer 1

print Parent.Nested() # works fine, print calls __str__ resulting in 'Child'