Today we developed this: 

class Account(object):
    def __init__(self, name, initial):
        self.name = name
        self.balance = initial
    def deposit(self, amount):
        self.balance += amount
    def withdraw(self, amount):
        self.balance -= amount
    def report(self):
        print self.balance

This is how it works: 

>>> 
>>> a = Account("Leo", 23)
>>> a
<__main__.Account object at 0x02C267B0>
>>> a.name
'Leo'
>>> a.balance
23
>>> a.deposit(34)
>>> a.report()
57
>>> a.withdraw(12)
>>> a
<__main__.Account object at 0x02C267B0>
>>> a.name
'Leo'
>>> a.balance
45
>>> a.report()
45
>>> b = Account("Mike Lucero", 12)
>>> a
<__main__.Account object at 0x02C267B0>
>>> b
<__main__.Account object at 0x02C267F0>
>>> a.report()
45
>>> b.report()
12
>>> b.deposit(100)
>>> a.report()
45
>>> b.report()
112
>>> a.name
'Leo'
>>> 

The definition above is of a class called Account. 

Account objects have:

a) one piece of data (instance variable) called balance

b) three identical behaviors with respect to their data
     -- deposit
     -- withdraw
     -- report

c) they also have a constructor.

Notice that if a = Account("Bryant", 30) then calling a.deposit(12)
essentially means that amount binds to 12 and self is pointing to the
object (a) whose function deposit has been invoked.