Classes

Overview

A class is a logical grouping, this can be variables, functions (called methods when in a class) and other classes (subclasses). This approach is called object orientated programming. This is a very brief example of creating a class and using them.

Example

If we want to create an object (a class) that holds the information we want to associate with a customer.
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class customer (object):
    def __init__(self, name = "", balance = 0, numberOfTransations = 0, discount = 0):
        self.name = name
        self.balance = 0
        self.numberOfTransations = 0
        self.discount = 0

    def credit(self, amount):
        self.numberOfTransations += 1
        self.balance = self.balance + amount

    def purchase(self, amount):
        self.numberOfTransations += 1
        self.balance = self.balance - amount   


dean = customer()

print (dean.balance)
print (dean.numberOfTransations)
print (dean.discount)

dean.credit(45)

print (dean.balance)

dean.purchase(10)

print (dean.balance)
print (dean.numberOfTransations)
print (dean.discount)

owen = customer()

owen.balance = 200
print (owen.balance)
Returns:
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0
0
0
45
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2
0
200
Note functions in a class are called methods.
We create a blueprint for the object we want when we create the class.
def __init__(self) - this is a special functions that is automatically executed when the class is created.




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