diff --git a/kjg/python-the-hard-way/e42.py b/kjg/python-the-hard-way/e42.py
new file mode 100644
index 0000000..bf71bbd
--- /dev/null
+++ b/kjg/python-the-hard-way/e42.py
@@ -0,0 +1,81 @@
+## Animal is-a object (yes, sort of confusing) look at the extra credit
+class Animal(object):
+    pass
+
+
+## Dog is-a Animal
+class Dog(Animal):
+    def __init__(self, name):
+        ## Dog has-a name
+        self.name = name
+
+        
+## Cat is-a Animal
+class Cat(Animal):
+    def __init__(self, name):
+        ## Cat has-a name
+        self.name = name
+
+        
+## Person is-a object
+class Person(object):
+    def __init__(self, name):
+        ## Person has-a name
+        self.name = name
+        ## Person has-a pet of some kind
+        self.pet = None
+
+        
+## Employee is-a person
+class Employee(Person):
+    def __init__(self, name, salary):
+        ## heritage from parents
+        super(Employee, self).__init__(name)
+        ## Employee has-a salary
+        self.salary = salary
+
+        
+## Fish is-a object
+class Fish(object):
+    pass
+
+
+## Salmon is-a Fish
+class Salmon(Fish):
+    pass
+
+
+## Halibut is-a Fish
+class Halibut(Fish):
+    pass
+
+
+## rover is-a Dog
+rover = Dog("Rover")
+
+## satan is-a Cat
+satan = Cat("Satan")
+
+## mary is-a Person
+mary = Person("Mary")
+
+## mary's pet is satan
+mary.pet = satan
+print(mary.pet.name)
+
+## frank is-a Employee
+frank = Employee("Frank", 120000)
+
+## frank's pet is rover
+frank.pet = rover
+print(frank.name)
+print(frank.pet.name)
+print(frank.salary)
+## flipper is-a Fish
+flipper = Fish()
+
+## crouse is-a Salmon
+crouse = Salmon()
+
+## harry is-a Halibut
+harry = Halibut()
diff --git a/kjg/python.org b/kjg/python.org
index 82cad8f..ecec546 100644
--- a/kjg/python.org
+++ b/kjg/python.org
@@ -147,3 +147,5 @@ How to use dictionary
 How to use class
 **** ex41
 practice class
+**** ex42
+review class and object