- The keyword class is fundamental to object oriented programming in Python.
- The class keyword is used to define any concept e.g., Complex Number, UI Window, Sparse Matrix and so on which are instantiated using their definitions.
- Methods and attributes can be defined for a class, which correspond to the behavior and state of an instance.
- Through class keyword a new user defined type is introduced into the Python Program.
- In Python, a concrete class defined is used to instantiate any number objects of the same type as the class.
- An abstract class acts as a base class for derived classes and provides a common abstraction or a common interface for the derived classes.
- In the picture below moulds of dolls are varying sizes are kept. Just like actual dolls are manufactured using these moulds the objects are instantiated using the classes.
Picture Courtesy: Joel Kramer
- Multiple inheritance is supported in Python through which a specialized concept or class is created by deriving from more than one class.
- This Python example defines a class NoteBook representing a primitive notebook.
- The Python program also instantiates the NoteBook class creating a NoteBook object.
myPageCount = 0;
myTitle = "";
myCoverOpen = False
myCurrentPage = 0;
def __init__(self, pageCount, title):
self.myPageCount = pageCount
self.myTitle = title
self.myCoverOpen = False
self.myCurrentPage = 1
self.myCoverOpen = True
self.myCurrentPage = self.myCurrentPage+1 # forward flip
nb = NoteBook(60, "Python Programming")
print("Page Count: %s"%(nb.myPageCount))
print("Page Title: %s"%(nb.myTitle))
Page Count: 60
Page Title: Python Programming