Master Python Revision Hub – 2026

01. Python Revision Tour

Reviewing the fundamentals: Tokens, Flow of Control, and Mutable/Immutable types.

Python Tokens Overview

for i in range(1, 5) print(i)

for i in range(1, 5):
    print(i)

List Slicing in Practice

L = [10, 20, 30, 40, 50, 60]

print(L[1:5])    # Output: [20, 30, 40, 50]
print(L[::-1])   # Output: [60, 50, 40, 30, 20, 10]
print(L[2:])     # Output: [30, 40, 50, 60]
                        

Mutable vs Immutable Types

02. Functions (Def & Arguments)

Understanding Python Functions

A function is a reusable block of code that performs a specific task. They are the building blocks of modular programming, helping to break complex problems into smaller, manageable pieces (e.g., `calc_tax()`, `send_email()`).

Types of Functions

Core Components

• def : Keyword to define
• name : Identifier for function
• parameters : Inputs received
• arguments : Values passed
• return : Output to caller
• call : Invoking execution

def greet(name)
print("Hello", name)

greet("Devanshu")

def greet(name):
    print("Hello", name)

greet("Devanshu")

Factorial Function Example

def factorial(n):
    result = 1
    # Loop from 1 to n
    for i in range(1, n + 1):
        result *= i
    return result  # Returns final value

num = 5
# Function Call
print("Factorial:", factorial(num)) 
# Output: Factorial: 120
                        

03. File Handling (Text, Binary, CSV)

Reading/Writing persistent data. Text files (`read()`, `readlines()`), Binary (`pickle`), and CSV modules are guaranteed 3-5 mark questions.

import pickle

def search_record(roll_no):
    found = False
    try:
        with open('student.dat', 'rb') as f:
            while True:
                rec = pickle.load(f)
                if rec['roll'] == roll_no:
                    print("Found:", rec)
                    found = True
                    break
    except EOFError:
        pass
    
    if not found:
        print("Record not found.")
                        

f = open('data.txt', 'w')
f.write(100) 
# TypeError: write() argument must be str, not int

f = open('data.txt', 'w')
f.write(str(100)) 
# Always convert non-string data to string for Text Files

04. Stacks (Data Structures)

Understanding Stack (LIFO Principle)

Stack is a linear data structure that follows the LIFO (Last In First Out) principle. Conceptualize it like a stack of plates: the last plate placed on top is the first one removed.

Core Stack Operations

• Push
  Add element to top (append)
• Pop
  Remove element from top (pop)
• Peek
  View top element (-1 index)
• Underflow
  Popping from empty stack

s.pop()
# Raises IndexError if stack is empty

if len(s) == 0:
    print("Underflow")
else:
    s.pop()

Menu-Driven Stack Implementation

s = []

def push():
    item = int(input("Enter element: "))
    s.append(item)
    print("Stack after push:", s)

def pop_element():
    if len(s) == 0:
        print("Underflow - Stack is empty")
    else:
        print("Popped element:", s.pop())

def display():
    if len(s) == 0:
        print("Stack is empty")
    else:
        print("Stack elements:", s)

while True:
    print("\n1. Push\n2. Pop\n3. Display\n4. Exit")
    choice = int(input("Enter choice: "))

    if choice == 1:
        push()
    elif choice == 2:
        pop_element()
    elif choice == 3:
        display()
    elif choice == 4:
        break
    else:
        print("Invalid choice")
                        

05. SQL & Interface

Structured Query Language involving `SELECT`, `GROUP BY`, `HAVING`, and Python-SQL connectivity (`mysql.connector`).

import mysql.connector as sqlt
con = sqlt.connect(host='localhost', user='root', passwd='password', database='school')
cursor = con.cursor()

cursor.execute("SELECT * FROM Student WHERE Marks > 90")
data = cursor.fetchall()

for row in data:
    print(row)

con.close()
                        

SELECT count(*) from Student;
# Counts ALL rows including NULLs (if any)

SELECT count(City) from Student;
# Ignores NULL values in the 'City' column!

06. Computer Networks

A. Network Types

"Memory Trick: PAN = Personal, LAN = Local, MAN = Metropolitan, WAN = World."

B. Key Topologies

C. Protocols & Terms

Mastering the 5-Mark Case Study