Course Topics
Introduction Python Overview Setting Up Python Python Syntax Basics First Steps with Python Comparing Python with Other Languages Basics Variables and Data Types Input and Output Type Conversion Comments and Code Readability Naming Conventions Control Flow Conditional Statements Loops in Python Loop Control Mechanisms Nested Control Structures Data Structures Working with Strings Lists Tuples Sets Dictionaries Comprehensions Iterators and Generators Functions Defining and Calling Functions Function Arguments and Parameters Lambda Functions Return Values Recursion Variable Scope in Functions Modules and Packages Importing Modules Built-in Modules Creating Custom Modules Working with Packages Virtual Environments Managing Packages with pip Object-Oriented Programming Classes and Objects Attributes and Methods Constructors and Initializers Inheritance and Polymorphism Encapsulation and Abstraction Class Methods and Static Methods Using super() and Method Resolution File Handling Reading and Writing Text Files File Modes and File Pointers Using Context Managers (with) Working with CSV Files Handling JSON Data Error Handling Types of Errors and Exceptions Try, Except, Finally Blocks Raising Exceptions Built-in vs Custom Exceptions Exception Handling Best Practices Advanced Python Decorators Advanced Generators Context Managers Functional Programming Tools Coroutines and Async Programming Introduction to Metaclasses Memory Management in Python Useful Libraries Math Module Random Module Date and Time Handling Regular Expressions (re) File and OS Operations (os, sys, shutil) Data Structures Enhancements (collections, itertools) Web APIs (requests) Data Analysis Libraries (NumPy, Pandas) Visualization Tools (matplotlib) Database Access SQLite in Python Connecting to MySQL/PostgreSQL Executing SQL Queries Using ORMs (SQLAlchemy Intro) Transactions and Error Handling Web Development Introduction to Web Frameworks Flask Basics (Routing, Templates) Django Overview Handling Forms and Requests Creating REST APIs Working with JSON and HTTP Methods Testing and Debugging Debugging Techniques Using assert and Logging Writing Unit Tests (unittest) Introduction to pytest Handling and Fixing Common Bugs Automation and Scripting Automating File Operations Web Scraping with BeautifulSoup Automating Excel Tasks (openpyxl) Sending Emails with Python Task Scheduling and Timers System Automation with subprocess

Python Overview

Overview

What is Python

Python is a popular programming language known for its simplicity and readability. It was created by Guido van Rossum and released in 1991. Python is used by beginners and professionals alike, and it's a top choice in fields like web development, data science, automation, machine learning, and more.

One of the main reasons Python is so popular is because its syntax is clean and easy to learn, even if you’ve never programmed before.

example:

print("Welcome")

This simple line prints the word Welcome to the screen. No extra code, no confusing symbols — just clear instructions.

Python emphasizes code that reads like English, which makes it a great starting point for beginners.

Why Learn Python?

Python is not just beginner-friendly — it’s also very powerful. Many large companies and platforms use Python behind the scenes, including Google, YouTube, Netflix, Instagram, and Dropbox.

Here are some key reasons to learn Python:

  • Easy to Read and Write: Python looks almost like English.
  • Flexible: You can use Python for websites, apps, games, data analysis, AI, and more.
  • Huge Community: Millions of people use Python, so help is always available online.
  • Tons of Libraries: Need to do something complex? Chances are someone has already written a Python library for it.
  • Career Opportunities: Python developers are in high demand.

example:

# A simple calculator
a = 5
b = 3
print("Sum:", a + b)

This is an example of how quickly you can build something useful in Python.

Real-World Uses of Python

Python is used in many different industries and fields. Here are some of the most common:

  • Web Development: Frameworks like Django and Flask make building websites easier.
  • Data Science and AI: Python is the #1 language for data analysis and machine learning.
  • Automation/Scripting: Automate boring tasks like renaming files or sending emails.
  • Game Development: Used with libraries like pygame.
  • Desktop Applications: Build apps using tkinter or PyQt.
  • Cybersecurity: Python is often used to write scripts for ethical hacking and analysis.

example (automation):

import os

files = os.listdir()
for file in files:
    print("Found file:", file)

This script lists all files in the current folder — a common first step in many automation tasks.

Key Features of Python

Here are some of the standout features that make Python unique:

  • Interpreted Language: You don’t need to compile your code. Just run it.
  • High-Level: You don’t need to manage memory or worry about how things work behind the scenes.
  • Dynamically Typed: You don’t have to declare variable types.
  • Extensive Libraries: From math to machine learning, Python has libraries for everything.
  • Portable: Python code works across Windows, Mac, and Linux with little to no changes.
  • Open Source: Python is free to use and distribute — even commercially.

example (dynamic typing):

x = 10      # Integer
x = "text"  # Now a string

print(x)

In Python, a variable can hold different types of data at different times. This flexibility makes coding faster.

Hello World in Python

Let’s write our first real program: the classic Hello, World! It’s the most common first program in any language.

example:

print("Hello, World!")

Save the file as hello.py and run it using your terminal or IDE. You should see:

Hello, World!

This simple line shows how approachable Python really is.

Python Versions

Python has two major versions:

  • Python 2 (no longer supported)
  • Python 3 (current and recommended)

You should always use Python 3, as Python 2 is outdated and no longer maintained. Most tutorials, including this one, use Python 3 syntax and features.

To check your version, run this in your terminal:

python --version

Or:

python3 --version

Who Uses Python?

Here are some well-known companies and projects that use Python:

  • Google: For system tools, automation, and internal services
  • Netflix: For data analysis and personalization
  • Instagram: Runs on Django, a Python framework
  • Spotify: For backend services and data pipelines
  • NASA: Uses Python in scientific research and simulations

This shows that Python is not just for beginners — it's also a professional tool used at the highest levels.

Summary

Python is one of the most popular and versatile programming languages today. Whether you're building a website, analyzing data, automating tasks, or diving into AI, Python gives you the tools and community to succeed.

In the next sections, we’ll explore how to install Python, write your first programs, and build a solid foundation in the language.

Welcome to your Python journey — let’s begin!

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