Getting container/parent object from within contained object

In Python, is it possible to get the object, say Foo, that contains another object, Bar, from within Bar itself? Here is an example of what I mean:

class Foo(object):
    def __init__(self):
        self.bar = Bar()
        self.text = "Hello World"

class Bar(object):
    def __init__(self):
        # I want to access the properties of the container object
        self.newText = foo.text

foo = Foo()

Is this possible?