University of Delhi Syllabus ยท Unit 4

Object-Oriented Programming

Classes, objects, methods and standard libraries

Learning Outcomes
  • Define classes with attributes and methods
  • Create and use objects
  • Apply object-oriented concepts in programs
  • Use Python standard libraries

Classes and Objects

A class is a user-defined blueprint for objects; the __init__ method initialises an object and self refers to the current instance. Objects are instances of a class, each holding its own attribute values.

class Student: def __init__(self, name, marks): self.name = name self.marks = marks

Methods

Methods are functions defined inside a class that operate on object data and are called on objects using dot notation.

class Student: def __init__(self, name, marks): self.name = name; self.marks = marks def result(self): return "Pass" if self.marks >= 40 else "Fail" print(Student("Asha", 72).result())

Standard Libraries

Python ships with a rich standard library; modules such as math, random, datetime and statistics are imported to reuse well-tested functionality.

import math, random print(math.sqrt(16), random.randint(1, 6))

Summary

This unit introduced classes, objects and methods, the basics of object-oriented programming in Python, and the use of standard library modules.

Exercises

  • Create a class BankAccount with methods to deposit, withdraw and display the balance.
  • Create a class to represent a rectangle and compute its area and perimeter.
  • Use the math and random modules to build a simple number-guessing game.