1 files changed, 83 insertions, 0 deletions
diff --git a/mit/extented_class_example/MITPerson.py b/mit/extented_class_example/MITPerson.py
new file mode 100644
index 0000000..b6bc856
--- /dev/null
+++ b/mit/extented_class_example/MITPerson.py
@@ -0,0 +1,83 @@
+#!/usr/bin/python3
+
+from Person import *
+
+class MITPerson(Person):
+
+    nextIdNum = 0 # next ID number to assign
+
+    def __init__(self, name):
+        Person.__init__(self, name)      # Initialize person's attributes
+        self.idNum = MITPerson.nextIdNum # MITPerson global attribute: unique ID
+        MITPerson.nextIdNum += 1
+
+    def getIdNum(self):
+        return self.idNum
+
+    # Sorting MIT people uses their ID number, not name
+    def __lt__(self, other):
+        return self.idNum < other.idNum
+
+    def speak(self, utterance):
+        return (self.name + " says: " + utterance)
+
+class Student(MITPerson):
+    pass
+
+class UG(Student):
+    def __init__(self, name, classYear):
+        MITPerson.__init__(self, name)
+        self.year = classYear
+
+    def getClass(self):
+        return self.year
+
+    def speak(self, utterance):
+        return MITPerson.speak(self, " Yo Bro: " + utterance)
+
+class Grad(Student):
+    pass
+
+class TransferStudent(Student):
+    pass
+
+
+
+# By creating a new 'blank' class Student, and making all UG, Grad and
+# TransferStudent classes inherit from it, we clean up the class inheritance a
+# bit, so, in the function below, we can simply us Student class, to check if an
+# object belongs to that class, instead of the old version (commented out below,
+# for historical perspective)
+def isStudent(obj):
+#    return isinstance(obj, UG) or isinstance(obj, Grad)
+    return isinstance(obj, Student)
+
+class Professor(MITPerson):
+    def __init__(self, name, department):
+        MITPerson__init__(self, name)
+        self.department = department
+
+    def speak(self, utterance):
+        new = "In course " + self.department + " we say "
+        return MITPerson.speak(self, new + utterance)
+
+    def lecture(self, topic):
+        return self.speak('it is obvious that ' + topic)
+
+m1 = MITPerson("Mark Zuckeberg")
+m2 = MITPerson("Bill Gates")
+m3 = MITPerson("Carlos Maiolino")
+p1 = Person("Drew Houston")
+
+
+s1 = UG("Matt Damon", 2017)
+s2 = Grad("Leonardo di Caprio")
+# Remember, comparison is done by using __lt__ method, which takes the instance
+# itself + another instance. When using the MITPerson instance, the __lt__
+# method uses the idNum attribute, which, an instance of Person class will not
+# have. But, using an instance of Person class, the __lt__ method, uses the
+# LastName, which, since MITPerson is a subclass of Person class, it also
+# contains a lastName attribute
+
+## print(p1 < m3) # Comparison works
+## print(m3 < p1) # Comparison does not work (Attribute error)