Now that you have an understanding of what object orientation is, we'll move on to Python. The first logical step is to create a class. You can define a class pretty much anywhere, including inside conditional statements. Defining a class is simple:

class SomeClass:

The next step is to add a bit of data to the class. There isn't anything special or unique about this step:

class SomeClass:

  "Just some class...that's all."

  someNumber = 127 + 1 / 360 * 2 + 1 / 2

  someString = 'Star Office 7'

You can also add methods. These are defined just like functions, except they take self as their first argument:

class SomeClass

  "Just some class...that's all."

  someNumber – 127 + 1 / 360 * 2 + 1 / 2

  someString = 'Star Office 7'

  def someFunction ( self ):

     return someString + ' tastes like chicken.'

  def someOtherFunction ( self ):

     return False

As you can see, it's pretty simple to create a class with data and methods.

Next, we must create an instance of our class, or an object derived from it. This is extremely simple and brief:

someObject = SomeClass()

We can now access the variables defined in our class:

someObject.someNumber

someObject.someString

Calling the methods defined in our class is also very simple:

someObject.someFunction()

someObject.someOtherFunction()

It is also possible to define attributes after we have created the object:

someObject.someRandomVariable = 5

Similarly, it is possible to clean up what we create:

del someObject.someRandomVariable

Let's say we want to define a variable when we first create an instance of our class. This can be accomplished by creating a special method of our class, __init__. The method will be executed when our class is first created.

class AnotherClass:

  def __init__ ( self, anotherArgument ):

      self.anotherArgument = anotherArgument

 

anotherObject = AnotherClass ( 'Hello object-oriented world.' )

print anotherObject.anotherArgument # "Hello object-oriented world."