Python Programming – Quick Review (Simple & Easy Guide)

Python Full Revision

This blog explains Python programming step by step in very simple English. Each topic is explained clearly, so beginners, students, and freshers can understand easily. Best for interviews and basics.

1. What is Python?

Python is a simple and powerful programming language.

  • Created by Guido van Rossum
  • Easy to read and write
  • Used in web development, data science, AI, automation

👉 In simple words: Python lets us talk to the computer using easy English-like words.

2. Why Learn Python?

  • Very easy for beginners
  • Less code compared to other languages
  • High job demand
  • Used in many fields

3. Python Program Structure

Python does not use {} brackets. It uses indentation (spaces).

print("Hello World")

4. Variables

Variables are used to store values.

age = 20
name = "Python"

5. Data Types

Data types tell Python what type of data we store.

TypeMeaning
intWhole number
floatDecimal
strText
boolTrue / False
listMultiple values

6. Input and Output

name = input("Enter name: ")
print(name)

7. Operators

Operators perform operations.

  • Arithmetic: + - * / %
  • Comparison: > < == !=
  • Logical: and or not

8. Conditional Statements

Used to make decisions.

if age >= 18:
    print("Adult")
else:
    print("Minor")

9. Loops

Loops repeat code.

for i in range(1, 6):
    print(i)

10. Functions

Functions are blocks of code.

def greet():
    print("Hello")

OOPS Concepts in Python (Very Simple)

11. What is OOPS?

OOPS means Object-Oriented Programming System.

👉 It is a way of writing programs using classes and objects.

12. Class and Object

Class

A class is a blueprint.

Object

An object is a real thing created from a class.

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

s1 = Student("Raj")

13. Constructor

A constructor runs automatically when an object is created.

class Test:
    def __init__(self):
        print("Constructor called")

14. Encapsulation

Encapsulation means binding data and methods together.

👉 It helps protect data.

Example:

class Person:
    def __init__(self):
        self.name = "Raj"

15. Inheritance

Inheritance allows one class to use another class properties.

👉 Child class uses parent class.

class Parent:
    def show(self):
        print("Parent class")

class Child(Parent):
    pass

16. Polymorphism

Polymorphism means one name, many forms.

👉 Same function works in different ways.

class A:
    def show(self):
        print("A")

class B(A):
    def show(self):
        print("B")

17. Abstraction

Abstraction means hiding internal details and showing only what is needed.

👉 Focus on what to do, not how.

18. Exception Handling

Used to handle errors.

try:
    a = 10/0
except:
    print("Error occurred")

19. File Handling

Used to store data permanently.

file = open("data.txt", "w")
file.write("Hello")
file.close()

20. Advantages of Python

  • Easy to learn
  • Less code
  • Powerful libraries

21. Disadvantages of Python

  • Slower than C/C++
  • Not good for low-level programming

Conclusion

Python with OOPS is very powerful and beginner-friendly. It is best for learning programming, interviews, and real-world projects.