class Dog(object):
def bark(self):
print "Woof!"fluffy = Dog()
fluffy.bark()Defining a class starts, predictably, with the class keyword followed by the
name of the class you are defining and a colon. The contents of that class
need to be indented one level so that Python knows where it stops. Note that
the object inside parentheses is there for object inheritance, which is
discussed later. For now, the least you need to know is that if your new class
is not based on an existing class, you should put object inside parentheses,
as shown in the previous code.
Functions inside classes work in much the same way as normal functions do
(although they are usually called methods); the main difference is that they
should all take at least one parameter, usually called self. This parameter is
filled with the name of the object the function was called on, and you need to
use it explicitly.
Creating an instance of a class is done by assignment. You do not need any
new keyword, as in some other languages; providing the parentheses makes
the creation known. Calling a function of that object is done using a period
and the name of the class to call, with any parameters being passed inside
parentheses.
Class and Object Variables
Each object has its own set of functions and variables, and you can
manipulate those variables independently of objects of the same type. In
addition, a class variable may be set to a default value for all classes, in which
case it can be manipulated globally.
This script demonstrates two objects of the dog class being created, each
with its own name:
Click here to view code image
class Dog(object):
name = "Lassie"
def bark(self):
print self.name + " says 'Woof!'"
def set_name(self, name):
self.name = name
fluffy = Dog()
fluffy.bark()