6 files changed, 215 insertions, 0 deletions
diff --git a/mit/extented_class_example/GradeBook.py b/mit/extented_class_example/GradeBook.py
new file mode 100644
index 0000000..36c25fb
--- /dev/null
+++ b/mit/extented_class_example/GradeBook.py
@@ -0,0 +1,94 @@
+#!/usr/bin/python3
+
+from MITPerson import *
+
+class Grades(object):
+    """ A mapping from students to a list of grades """
+    def __init__(self):
+        """ Create empty grade book """
+        self.students = []      # List of student objects
+        self.grades = {}        # maps idNum -> list of grades
+        self.isSorted = True    # true if self.students is sorted
+
+    def addStudent(self, student):
+        """
+            Assumes: student is of type Student
+            Add student to the grade book
+        """
+        if student in self.students:
+            raise ValueError('Duplicated student')
+
+        self.students.append(student)
+        self.grades[student.getIdNum()] = []    # dict is a ID:List pair
+        self.isSorted = False
+
+    def addGrade(self, student, grade):
+        """
+            Assumes: grade is a float
+            Add grade to the list of grades for student
+        """
+        try:
+            self.grades[student.getIdNum()].append(grade)
+        except KeyError:
+            raise ValueError('Student not in grade book')
+
+    def getGrades(self, student):
+        """ Return a list of grades for student """
+        try:    # Return a COPY of student's grades
+            return self.grades[student.getIdNum()][:]
+        except KeyError:
+            raise ValueError('Student not in grade book')
+
+    def allStudents(self):
+        """ Return a list of the students in the grade book """
+        if not self.isSorted:
+            self.students.sort()
+            self.isSorted = True
+        return self.students[:] # Return a COPY of students, so we avoid any
+                                # externalmodification to the original list
+
+
+
+### TESTS
+
+def gradeReport(course):
+    """ Assumes: course is of type grades """
+
+    report = []
+
+    for s in course.allStudents():
+        tot = 0.0
+        numGrades = 0
+
+        for g in course.getGrades(s):
+            tot += g
+            numGrades += 1
+
+        try:
+            mean = tot/numGrades
+            report.append(str(s) + '\'s mean grade is ' + str(mean))
+        except ZeroDivisionError:
+            report.append(str(s) + ' has no grades')
+
+    return ' \n'.join(report)
+
+
+six00 = Grades()
+ug3 = UG('Drew Houston', 2017)
+ug1 = UG('Matt Damon', 2018)
+ug2 = UG('Ben Affleck', 2019)
+ug4 = UG('Mark Zuckerberg', 2017)
+g1 = Grad('Bill Gates')
+g2 = Grad('Steve Wozniak')
+
+six00.addStudent(g1)
+six00.addStudent(ug2)
+six00.addStudent(ug1)
+six00.addStudent(g2)
+six00.addStudent(ug4)
+six00.addStudent(ug3)
+
+six00.addGrade(g1, 90)
+six00.addGrade(g2, 45)
+six00.addGrade(ug1, 80)
+six00.addGrade(ug2, 75)
diff --git a/mit/extented_class_example/GradeBook.pyc b/mit/extented_class_example/GradeBook.pyc
new file mode 100644
index 0000000..2762139
--- /dev/null
+++ b/mit/extented_class_example/GradeBook.pyc
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)
diff --git a/mit/extented_class_example/MITPerson.pyc b/mit/extented_class_example/MITPerson.pyc
new file mode 100644
index 0000000..3bc833c
--- /dev/null
+++ b/mit/extented_class_example/MITPerson.pyc
diff --git a/mit/extented_class_example/Person.py b/mit/extented_class_example/Person.py
new file mode 100644
index 0000000..481dd69
--- /dev/null
+++ b/mit/extented_class_example/Person.py
@@ -0,0 +1,38 @@
+#!/usr/bin/python3
+
+import datetime
+
+class Person(object):
+    def __init__(self, name):
+        """Create a person called name"""
+        self.name = name
+        self.birthday = None
+        self.lastName = name.split(' ')[-1]
+
+    def getLastName(self):
+        """return self's last name"""
+        return self.lastName
+
+    def __str__(self):
+        """return self's name"""
+        return self.name
+
+
+    def setBirthday(self,month,day,year):
+        """sets self's birthday to birthDate"""
+        self.birthday = datetime.date(year,month,day)
+
+    def getAge(self):
+        """returns self's current age in days"""
+        if self.birthday == None:
+            raise ValueError
+        return (datetime.date.today() - self.birthday.days())
+
+    def __lt__(self, other):
+        """
+        return True if self's name is lexicographically less than other's
+        name, and False otherwise
+        """
+        if self.lastName == other.lastName:
+            return self.name < other.name
+        return self.lastName < other.lastName
diff --git a/mit/extented_class_example/Person.pyc b/mit/extented_class_example/Person.pyc
new file mode 100644
index 0000000..17f7ef7
--- /dev/null
+++ b/mit/extented_class_example/Person.pyc