objects in python


  • At its simplest, an object is some code plus data structures that is smaller than a whole program
  • Defining a function allows us to store a bit of code and give it a name and then later invoke that code using the name of the function.
  • An object can contain a number of functions (which we call “methods”) as well as data that is used by those functions. We call data items that are part of the object “attributes”
  • We use the class keyword to define the data and code that will make up each of the objects
  • . The class keyword includes the name of the class and begins an indented block of code where we include the attributes (data) and methods (code).
  • class PartyAnimal:
       x = 0
    
       def party(self) :
         self.x = self.x + 1
         print("So far",self.x)
    
    an = PartyAnimal()
    an.party()
    an.party()
    an.party()
    PartyAnimal.party(an)
  • Each method looks like a function, starting with the def keyword and consisting of an indented block of code. This example has one attribute (x) and one method
  • (party). The methods have a special first parameter that we name by convention self.