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🐍 PYTHON PROGRAMMING
Complete Notes • Class 6 • Absolute Beginner to Advanced
✅Step-by-step explanations with real-life examples
✅Every concept explained like you're 11 years old
✅Hundreds of code examples, tips, and exercises
✅Tables, diagrams, and memory tricks
✅Practice questions after every chapter
"Learning Python is like learning a superpower. Once you know it, you can make computers do anything you want!"
TABLE OF CONTENTS
Chapter 1: Introduction to Python
Chapter 2: Setting Up Python on Your Computer
Chapter 3: Your First Python Program
Chapter 4: Variables and Data Types
Chapter 5: Numbers and Math Operations
Chapter 6: Strings – Playing with Text
Chapter 7: Getting Input from the User
Chapter 8: Making Decisions – if / elif / else
Chapter 9: Loops – Doing Things Again and Again
Chapter 10: Lists – Storing Many Things
Chapter 11: Tuples – Unchangeable Lists
Chapter 12: Dictionaries – Key-Value Pairs
Chapter 13: Sets – Unique Collections
Chapter 14: Functions – Reusable Code Blocks
Chapter 15: Scope and Namespaces
Chapter 16: Modules and Imports
Chapter 17: File Handling – Reading & Writing Files
Chapter 18: Error Handling – try / except
Chapter 19: Object-Oriented Programming (OOP)
Chapter 20: Inheritance and Polymorphism
Chapter 21: Advanced Functions
Chapter 22: List Comprehensions & Generators
Chapter 23: Regular Expressions
Chapter 24: Working with Dates and Time
Chapter 25: Python Projects & Next Steps
CHAPTER 1
Introduction to Python
▶ What is Python?
Python is a programming language. A programming language is a special set of words and rules that
we use to give instructions to a computer. Just like we use English or Hindi to talk to people, we use
Python to talk to computers!
Python was created by a Dutch programmer named Guido van Rossum. He started working on it in
1989 and released it in 1991. He named it 'Python' not after the snake, but after a British comedy
TV show called 'Monty Python's Flying Circus' that he liked!
🐍 IMPORTANT: Python is one of the most popular programming languages in the world today.
Companies like Google, YouTube, Netflix, Instagram, Spotify, and NASA all use Python!
▶ Why Learn Python?
🟢 Easy to read and write – Python looks almost like plain English
🟢 Free to use – Anyone can download and use Python for free
🟢 Works everywhere – Python works on Windows, Mac, and Linux
🟢 Lots of uses – websites, games, science, AI, robots, and more
🟢 Huge community – Millions of people use Python; help is always available
🟢 Perfect for beginners – Best first language to learn
▶ What Can You Do With Python?
Area What Python Can Do Famous Example
Web Development Build websites and web apps Instagram, Pinterest Data Science Analyse huge amounts of data Used by scientists worldwide Artificial Intelligence Create smart programs ChatGPT uses Python Game Development Make fun games Many indie games
Automation Automate boring tasks Auto-fill forms, send emails Robotics Control robots NASA Mars Rover software Cybersecurity Find and fix security problems Ethical hacking tools Finance Analyse stocks and numbers Used by banks
▶ How Does a Computer Understand Python?
Computers only understand 0s and 1s (binary). So Python code cannot be directly understood by
the hardware. Python uses a special program called an Interpreter that reads your Python code line
by line and translates it into instructions the computer can follow.
🐍 ANALOGY: Think of the Python Interpreter as a live translator. Imagine you speak only Hindi,
and your friend speaks only English. A translator stands between you and converts your Hindi
words into English instantly, sentence by sentence. The Python interpreter does the same — it
converts your Python code into computer language instantly.
▶ Python Versions
There are two major versions of Python you will hear about:
Version Released Should You Use It? Notes
Python 2 2000 ❌NO Old version, no longer supported since 2020 Python 3 2008 ✅YES Current version. We use this in all our lessons
🐍 IMPORTANT: Always use Python 3. Python 2 is dead. All new projects use Python 3.
▶ Chapter 1 – Quick Quiz
1. Who created Python and when?
2. Why is Python called 'Python'?
3. Name 3 companies that use Python.
4. What does the Python Interpreter do?
5. Which version of Python should you use – Python 2 or Python 3? Why?
CHAPTER 2
Setting Up Python on Your Computer
▶ Step 1 – Download Python
6. Open your web browser (Chrome, Firefox, etc.)
7. Go to: www.python.org
8. Click on 'Downloads'
9. Click on the big yellow button that says 'Download Python 3.x.x'
10. Wait for the file to download
▶ Step 2 – Install Python (Windows)
11. Double-click the downloaded file
12. ⭐VERY IMPORTANT: Check the box that says 'Add Python to PATH' (This is at the bottom of
the installer window)
13. Click 'Install Now'
14. Wait for installation to finish
15. Click 'Close'
🐍 IMPORTANT: If you forget to check 'Add Python to PATH', Python will not work properly. You
will have to uninstall and reinstall it.
▶ Step 3 – Check If Python Is Installed
Open the Command Prompt (Windows) or Terminal (Mac/Linux) and type:
python --version
You should see something like:
Python 3.12.
🐍 TIP: On some computers you might need to type python 3 --version instead of python --version
▶ Understanding the Python Shell (IDLE)
Python comes with a built-in editor called IDLE (Integrated Development and Learning
Environment). Let's understand the two modes:
Mode What It Is How to Open Best For
Interactive Shell Type one line, see result instantly Open IDLE → Shell window opens Quick tests and experiments Script Mode Write a full program in a file File → New File in IDLE Writing complete programs
▶ Installing VS Code (Recommended Editor)
VS Code (Visual Studio Code) is a free, powerful code editor made by Microsoft. Most professional
programmers use it. Here's how to install it:
16. Go to code.visualstudio.com
17. Click 'Download for Windows' (or your operating system)
18. Install it like a normal program
19. Open VS Code
20. Go to Extensions (Ctrl+Shift+X)
21. Search for 'Python' and install the extension by Microsoft
🐍 TIP: VS Code makes coding much easier because it shows errors, suggests code as you type, and
highlights your code in colours!
▶ Online Python Editors (No Installation Needed!)
If you cannot install Python on your computer, you can use online editors:
Website Link Features
Replit replit.com Free, save your projects, share with others Python Anywhere pythonanywhere.com Free, runs Python in the cloud Online Python onlinepython.com Simple, instant, no sign-up needed Google Colab colab.research.google.com Great for science and AI projects
CHAPTER 3
Your First Python Program
▶ Hello, World!
By tradition, every programmer's first program is called 'Hello, World!'. It simply prints those
words on the screen. Here is how you do it in Python:
print("Hello, World!")
When you run this program, you will see:
Hello, World!
🐍 EXPLANATION: print() is a built-in Python function. A function is like a magic word that does
something for you. The print() function displays whatever you put inside the parentheses ( ) on the
screen.
▶ Understanding print()
The print() function can display many things:
print("Hello, World!") # prints text print(42) # prints a number print(3.14) # prints a decimal number print("I love Python!") # prints another message print() # prints a blank line
▶ What Are Comments?
In the code above, you saw lines starting with #. These are called COMMENTS. Comments are notes
that YOU write for yourself (or other programmers). Python completely ignores comments — they
are not executed.
This is a comment
Python will ignore this line
print('Hello') # This comment is at the end of a line
Comments help you remember what your code does
Always write clear comments!
🐍 TIP: Good programmers always write comments. Future-you will thank present-you when you
read your code 6 months later and still understand it!
▶ Single Quotes vs Double Quotes
In Python, you can use both single quotes (' ') and double quotes (" ") for text. They work the same
way!
print("Hello") # double quotes - works! print('Hello') # single quotes - also works!
Use double quotes when your text has an apostrophe:
print("I'm learning Python!") # need backslash OR use double quotes print("I'm happy!") # backslash before apostrophe
▶ Printing Multiple Things
Method 1: Use a comma to print multiple items
print("My name is", "Arjun") print("I am", 11, "years old")
Method 2: Combine strings with +
print("Hello " + "World")
Method 3: Print multiple lines
print("Line 1") print("Line 2") print("Line 3")
▶ Special Print Effects with Escape Characters
26. Print the following on one single line using end=: Hello My name is Python
CHAPTER 4
Variables and Data Types
▶ What is a Variable?
A variable is like a labelled box that stores a value. Imagine you have a box with 'Age' written on it,
and inside the box is the number 11. In Python, you can create such boxes and store values in them.
🐍 REAL LIFE ANALOGY: Think of a variable as a glass jar with a label. You can put anything in the
jar — water, juice, sand. The label tells you what's inside. In Python, the label is the variable name,
and the contents are the variable value.
▶ Creating Variables
Creating a variable in Python is very easy. You just write the name, then =, then the value:
Syntax: variable_name = value
name = 'Arjun' age = 11 height = 4. is_student = True
Print the variables
print(name) # Output: Arjun print(age) # Output: 11 print(height) # Output: 4. print(is_student) # Output: True
▶ Rules for Naming Variables
Not every word can be used as a variable name. Python has rules:
Rule Correct Wrong
Must start with a letter or _ name, _count, age1 1name, @age Can contain letters, digits, _ my_name, score2 my-name, my name
price = 99.99 # price pi = 3.14159 # famous mathematical constant weight = - 2.5 # negative float print(type(height)) # Output:
◆ 3. String (str) – Text
name = "Arjun" city = 'Mumbai' sentence = "I love Python programming!" empty = "" # empty string print(type(name)) # Output:
◆ 4. Boolean (bool) – True or False
is_student = True has_pet = False loves_coding = True print(type(is_student)) # Output:
Note: True and False must start with CAPITAL letters
true and false are WRONG in Python!
◆ 5. NoneType – No Value
None means 'nothing' or 'no value'
result = None print(result) # Output: None print(type(result)) # Output:
▶ The type() Function
The type() function tells you what data type a value is. This is very useful for debugging!
print(type(42)) # print(type(3.14)) # print(type("hello")) # print(type(True)) # print(type(None)) #
▶ Type Conversion (Casting)
Sometimes we need to change a value from one type to another. This is called type conversion or
casting:
int() - converts to integer
x = int("42") # string to int → 42 y = int(3.9) # float to int → 3 (truncates, doesn't round!) z = int(True) # bool to int → 1
float() - converts to float
a = float("3.14") # string to float → 3. b = float(5) # int to float → 5.
str() - converts to string
c = str(42) # int to string → '42' d = str(3.14) # float to string → '3.14'
bool() - converts to boolean
print(bool(1)) # True print(bool(0)) # False print(bool("")) # False (empty string) print(bool("hi")) # True (non-empty string)
🐍 IMPORTANT: When converting a float to int with int(), Python just cuts off the decimal part.
int(3.9) gives 3, NOT 4. Use round() if you want proper rounding!
▶ Multiple Assignment
Assign same value to multiple variables
x = y = z = 0 print(x, y, z) # 0 0 0
Assign different values in one line
a, b, c = 10, 20, 30 print(a) # 10 print(b) # 20 print(c) # 30
Swap two variables (very Pythonic!)
x = 5 y = 10
CHAPTER 5
Numbers and Math Operations
▶ Basic Arithmetic Operators
Operator Name Example Result Notes
- Addition 5 + 3 8 Adds two numbers
- Subtraction 10 - 4 6 Subtracts second from first
- Multiplication 6 * 7 42 Multiplies two numbers / Division 10 / 3 3.333... Always gives a float! // Floor Division 10 // 3 3 Divides and rounds down % Modulo 10 % 3 1 Gives the remainder ** Exponentiation 2 ** 8 256 Raises to the power
▶ Understanding Each Operator
Addition
print(5 + 3) # 8 print(2.5 + 1.5) # 4.
Subtraction
print(10 - 4) # 6 print(5 - 8) # - 3
Multiplication
print(6 * 7) # 42 print(3 * 3.0) # 9.
Division (always returns float)
print(10 / 2) # 5.0 (not 5!) print(7 / 2) # 3.
Floor Division (rounds DOWN)
print(10 // 3) # 3 print(7 // 2) # 3
print(-7 // 2) # - 4 (rounds towards negative infinity)
Modulo (remainder)
print(10 % 3) # 1 (10 = 33 + 1) print(15 % 4) # 3 (15 = 43 + 3) print(8 % 2) # 0 (8 is perfectly divisible by 2)
Exponentiation (power)
print(2 ** 10) # 1024 print(3 ** 3) # 27 print(9 ** 0.5) # 3.0 (square root!)
▶ BODMAS / Order of Operations
Python follows the same BODMAS rules you learn in Maths class. This determines which operation
is calculated first when you have multiple operators in one expression.
Order Letter Stands For Example
1st B Brackets ( ) 2nd O Orders / Exponents ** (powers, roots) 3rd D Division / or // 3rd M Multiplication * 4th A Addition + 4th S Subtraction -
Without brackets
print(2 + 3 * 4) # 14 (3*4 first, then +2) print(10 - 6 / 2) # 7.0 (6/2 first, then 10 - 3)
With brackets (changes order!)
print((2 + 3) * 4) # 20 (2+3 first, then *4) print((10 - 6) / 2) # 2.0 (10-6 first, then /2)
Complex expression
result = 2 + 3 * 4 ** 2 / 8 - 1
Step 1: 4**2 = 16
Step 2: 3*16 = 48
Step 3: 48/8 = 6.
Step 4: 2+6.0 = 8.
Step 5: 8.0-1 = 7.
print(result) # 7.
▶ Useful Math Functions
