i have a class which inherets a attribute from a super-class. this attribute is a class itself.

class classA(superClass):
 def func(self,x):
  if self.attributeB is None:
   do somthing  

and in the other class i have

class superClass:
 self.attributB = classB()

i get the error

AttributeError: class classA has no attribute 'attributeB'

when i access the attribute like i showed but if on command line i can see it works,

x = classA()
x.attributeB is None 
True

so the test works. whats going on in the above code?