CodeZen Notes
COMPLETE STUDY NOTES
Class 12 — Computer Science with Python
Session 2024–25 | Exam Ready Edition
CBSE Board Examination Preparation | Python + Networking + SQL + Data Structures
, ⚡ CodeZen Notes Class 12 — Computer Science with Python Session 2024–25 | Exam Ready Edition
📋 Table of Contents
1. Unit 1: Python Fundamentals Review
2. Unit 2: Functions & Exception Handling
3. Unit 3: File Handling (Text Files)
4. Unit 4: Binary File Handling
5. Unit 5: CSV File Handling
6. Unit 6: Data Structures (Stack & Queue)
7. Unit 7: Computer Networks
8. Unit 8: Database Management & MySQL
9. Unit 9: Python–MySQL Interface
10. Unit 10: Quick Revision Flashcards
, ⚡ CodeZen Notes Class 12 — Computer Science with Python Session 2024–25 | Exam Ready Edition
🐍 Unit 1: Python Fundamentals Review
Python is a high-level, interpreted programming language that is widely taught at Class 12 level. Below
are its key qualities and core concepts you must know for the exam.
▸ Core Features of Python
Interpreted: Python runs code one line at a time — no compilation step needed.
Open Source: Free to download, modify, and distribute for any purpose.
Portable: The same Python program runs on Windows, Mac, or Linux without changes.
Object-Oriented: Supports both procedural and object-oriented programming styles.
Dynamically Typed: You do not need to declare variable types — Python figures it out at runtime.
Extensible: Python can call code written in C, C++, or Java.
▸ How You Can Write Python Code
• Interactive Mode — Type and run one command at a time in the Python shell (IDLE prompt). Good for
quick tests.
• Script Mode — Write a full program in a .py file and execute it all at once. Used for real projects.
💡 Exam Tip: CBSE often asks: 'What is the difference between interactive and script mode?' — remember:
interactive = one line at a time; script = entire file runs together.
▸ Indentation & Comments
Python uses indentation (spaces/tabs at the start of a line) to define code blocks. Other languages use
braces {} for this purpose.
if age >= 18:
print('Adult') # This line belongs to the if block
print('Done') # This is outside the if block
• Single-line comment — starts with # symbol.
• Multi-line comment — enclose text in triple quotes ''' or """.
▸ Python Tokens
A token is the smallest meaningful unit in a Python program. Every statement is made up of tokens.
Token Type What It Is Example
Keyword Reserved words Python if, else, for, while, def, return
already uses — cannot be
used as names.
Identifier Names you give to variables, student_name, calc_total,