🐍 Python Handbook

Overview

Python is a high-level, interpreted, general-purpose programming language emphasizing readability and simplicity. It is widely used in web development, data science, AI/ML, automation, and scripting.

Version Python 3.x  Paradigm OOP, Functional, Procedural  Typing Dynamic

Core Concepts

Variables & Data Types

• int, float, complex — numeric types
• str — immutable string
• list — mutable ordered collection
• tuple — immutable ordered collection
• dict — key-value pairs
• set — unordered unique elements
• bool — True / False

Control Flow

• if / elif / else
• for item in iterable
• while condition
• break, continue, pass

Functions

• Defined with def
• Lambda: lambda x: x * 2
• *args and **kwargs for variable arguments
• Decorators with @decorator

Object-Oriented Programming

• Class defined with class MyClass:
• Constructor: def __init__(self)
• Inheritance: class Child(Parent)
• Special methods: __str__, __repr__, __len__
• Encapsulation via _private and __name_mangling

Key Libraries & Frameworks

Category	Library / Framework
Web	Django, Flask, FastAPI
Data Science	NumPy, Pandas, Matplotlib
Machine Learning	TensorFlow, PyTorch, scikit-learn
Automation	Selenium, Playwright, PyAutoGUI
Testing	pytest, unittest
API	requests, httpx

Common Interview Topics

• List comprehensions vs generator expressions
• GIL (Global Interpreter Lock)
• Mutable vs immutable objects
• deepcopy vs copy
• Context managers (with statement)
• Async programming with asyncio
• Memory management & garbage collection