Object and Class in python

Object Oriented Programming features are:

1. Encapsulation
2. Inheritance
3. Polymorphism
4. Abstraction

Note the followings:

• These features neither belong to Python nor to any other programming language.
• OOP features are Global.
• Any programming language can implement the functionality of OOP.
• The 2 concepts used in OOP implementation are
  • Object
  • Class

Object: A real world entity consists

1. Identity : Used to access the object uniquely.
2. Variables : Stores information of object.
3. Methods : To process the data of object.

class:

• “class” is a keyword.
• “class” is the complete representation of object.
• Without class, we cannot define object in object oriented programming.
• Class is also called Plan or Model or Blue print of object.
• Based on single model(class), we can define any number of objects(similar type).

Procedure oriented programming:

• C is procedure oriented programming language.
• We define programs in procedure oriented programming.
• One program can access the information of another program directly.
• The following diagram explains the communication in C application.

Object oriented programming:

• C++, Java, Python and many languages are object oriented.
• We define objects in object oriented application.
• Object information is secured.
• One object(program) cannot access the information of another object directly.
• We classify the object information(data) using access modifiers concept.
• The following diagram explains the communication between 2 objects.

The way of writing program:

• In procedure oriented approach, we define the program elements directly such as variables and functions.
• In object oriented approach, every element must belong to class.
• Class represents object.
• We separate the information of each object using class.