I'm having trouble understanding scope of a variable in a subclass

[Pyenos]

Thanks for clarifying the definitions of nested class and
subclass. However, it did not solve my original problem, and I have
redefined my question:

class Class1:
    class Class2:
        class Class3:
            def __init__(self):
                self.var="var"
            class Class4:
                print Class1.Class2.Class3.var

This code gives me the error:
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
  File "<stdin>", line 2, in Class1
  File "<stdin>", line 3, in Class2
  File "<stdin>", line 6, in Class3
  File "<stdin>", line 7, in Class4
NameError: name 'Class1' is not defined

I have tried:

class Class1:
        class Class2:
                def __init__(self):
                        var="var"
print Class1.Class2().var #this works

And, this worked. It is very strange that nested loop somehow fails to
work when the innermost class has indentation level greater than two.