How can I use objects which belong to one class, in another different class? I tried different things, but I still do not get a solution. Let ́s say I have the following example code:

class ClassA():
 def __init__(self):
 print "I am ClassA"
 def methodA(self):
 print "Method executed"
 
class ClassB():
 def __init__(self):
 print "I am ClassB"
 
 self.varB = 0 
 def methodB(self): 
 if self.varB == 0:
 # Error here
 self.objectA.methodA()
 else:
 print "Method not executed"
class ClassC():
 def __init__(self):
 print "I am ClassC"
 
 self.objectA = ClassA()
 self.objectA.methodA()
#Step 1:
obj1 = ClassC()
#Step 2:
obj2 = ClassB() 
#Step 3: (Gives error)
obj2 = methodB()

In this example, I have three classes. In ClassC, I create an instance of ClassA, which is used to execute the respective method (methodA). If afterwards we procceed with "Step 1", the output is:

I am ClassC

I am ClassA

Method executed

Then, in "Step 2", I create a new object of ClassB. Following to the last output, we get now as well:

I am ClassB

The problems comes with "Step 3", when I execute the methodB for the last object. The error:

AttributeError: ClassB instance has no attribute 'objectA'

I have very clear the origin of the error. I can ́t simply use the instance that I created in ClassC, inside the method of ClassB.

Does anyone know, how could I access from ClassB, an instance (in this case objectA) that I created in other class (ClassC)?

How can I use objects which belong to one class, in another different class? I tried different things, but I still do not get a solution. Let ́s say I have the following example code:

class ClassA():
 def __init__(self):
 print "I am ClassA"
 def methodA(self):
 print "Method executed"
 
class ClassB():
 def __init__(self):
 print "I am ClassB"
 
 self.varB = 0 
 def methodB(self): 
 if self.varB == 0:
 # Error here
 self.objectA.methodA()
 else:
 print "Method not executed"
class ClassC():
 def __init__(self):
 print "I am ClassC"
 
 self.objectA = ClassA()
 self.objectA.methodA()
#Step 1:
obj1 = ClassC()
#Step 2:
obj2 = ClassB() 
#Step 3: (Gives error)
obj2 = methodB()

In this example, I have three classes. In ClassC, I create an instance of ClassA, which is used to execute the respective method (methodA). If afterwards we procceed with "Step 1", the output is:

I am ClassC

I am ClassA

Method executed

Then, in "Step 2", I create a new object of ClassB. Following to the last output, we get now as well:

I am ClassB

The problems comes with "Step 3", when I execute the methodB for the last object. The error:

AttributeError: ClassB instance has no attribute 'objectA'

I have very clear the origin of the error. I can ́t simply use the instance that I created in ClassC, inside the method of ClassB.

Does anyone know, how could I access from ClassB, an instance (in this case objectA) that I created in other class (ClassC)?