# a typical Python class example
# newer class convention uses inheritance place holder (object) 
 
class Account(object):
    # __init__() initializes a newly created class instance,
    # 'self' refers to the particular class instance
    # and also carries the data between the methods.
    # You have to supply the initial account balance 
    # during creation of the class instance.
    def __init__(self, initial):
        self.balance = initial
 
    def deposit(self, amt):
        # a function within a class is called a method
        # self always starts the argument list of a method
        self.balance = self.balance + amt
 
    def withdraw(self,amt):
        self.balance = self.balance - amt
 
    def getbalance(self):
        return self.balance 
 
 
# create two new class instance, Mary's and Tom's account
mary = Account(1000.00) # start with initial balance of 1000.00
tom = Account(3000.00)  # tom is lucky he starts with 3000.00
 
# Mary makes deposits and a withdrawel
mary.deposit(500.00)
mary.deposit(23.45)
mary.withdraw(78.20)
 
# Tom also accesses his account
tom.withdraw(1295.50)
 
# now look a the account balances
print "Mary's balance = $%0.2f" % mary.getbalance()  # $1445.25
print "Tom's balance  = $%0.2f" % tom.getbalance()   # $1704.50

# class Teacher and class Student inherit from class SchoolMember
 
# the base or super class
class SchoolMember(object):
    '''represents any school member'''
    def __init__(self, name, age):
        self.name = name
        self.age = age
 
    def detail(self):
        '''show name and age, stay on same line (trailing comma)'''
        print 'Name: %-13s Age:%s' % (self.name, self.age),
 
# use the base class as argument to inherit from
class Teacher(SchoolMember):
    '''represents a teacher'''
    def __init__(self, name, age, subject):
        # call the base class constructor ...
        # it assigns name, age to self.name, self.age
        SchoolMember.__init__(self, name, age)
        self.subject = subject
 
    def detail(self):
        '''teaches this course'''
        SchoolMember.detail(self)
        print 'Teaches course: %s' % self.subject
 
class Student(SchoolMember):
    '''represents a student'''
    def __init__(self, name, age, grades):
        SchoolMember.__init__(self, name, age)
        self.grades = grades
 
    def detail(self):
        '''student grades'''
        SchoolMember.detail(self)
        print 'Average grades: %d' % self.grades
 
# teacher has name age and subject taught
t1 = Teacher('Mr. Schard', 40, 'Beginning Python 101')
# student has name, age and average grade (max 100)
s1 = Student('Abigale Agat', 20, 92)
s2 = Student('Bertha Belch', 22, 65)
s3 = Student('Karl Kuss', 21, 98)
s4 = Student('Tom Tippit', 22, 77)
s5 = Student('Zoe Zeller', 20, 88)
 
print '-'*55
 
# list of instances, Teacher t1 and Students s1 ... s5
members = [t1, s1, s2, s3, s4, s5]
sumgrades = 0
for member in members:
    memberType = member.detail()
    try:
        sumgrades += member.grades
    except AttributeError:
        pass # this would be a teacher, has no grades so skip
 
print "\n%s's students class-average grades = %d" % (t1.name, sumgrades/5)
 
"""
output -->
Name: Mr. Schard    Age:40 Teaches course: Beginning Python 101
Name: Abigale Agat  Age:20 Average grades: 92
Name: Bertha Belch  Age:22 Average grades: 65
Name: Karl Kuss     Age:21 Average grades: 98
Name: Tom Tippit    Age:22 Average grades: 77
Name: Zoe Zeller    Age:20 Average grades: 88
 
Mr. Schard's students class-average grades = 84
"""