Introduction to Python

What is Python?

Python is a high-level, interpreted, general-purpose programming language. It was created by Guido van Rossum and its first version was released in 1991.

Main Features

• Easy to learn: Its syntax is clear and similar to English
• Versatile: Used in web, data science, AI, automation, games…
• Large community: Thousands of libraries available
• Cross-platform: Works on Windows, macOS, and Linux

Where is Python used?

Installing Python

Step 1: Download Python

Visit the official Python page: https://www.python.org/downloads/

Step 2: Verify the installation

Open a terminal (CMD on Windows, Terminal on macOS/Linux) and type:

1python --version

You should see something like:

Python 3.12.0

Step 3: Test the interactive interpreter

Type python in the terminal to open the interactive interpreter:

1>>> print("Hello, Python!")
2Hello, Python!
3>>> 2 + 2
44
5>>> exit()

Your first program

Let’s create a simple program. Create a file called hello.py with the following content:

1# My first Python program
2print("Hello, world!")
3
4name = input("What's your name? ")
5print(f"Nice to meet you, {name}!")

Run it from the terminal:

1python hello.py

Set up your editor: Visual Studio Code

So far we’ve used the terminal to run Python, and you could write code in Notepad if you wanted. But that would be like trying to cook a banquet with just a knife and a pan: technically possible, but unnecessarily difficult.

Visual Studio Code (VSCode) is a free code editor that will give you superpowers: syntax highlighting, autocomplete, error detection before running, and much more. It’s like going from that basic kitchen to a fully equipped professional kitchen.

Step 1: Install VSCode

1. Go to https://code.visualstudio.com/
2. Download the version for your operating system
3. Install it (next, next, install… you know how it goes)

Step 2: Install the Python extension

VSCode by itself doesn’t know anything about Python. We need to teach it:

1. Open VSCode
2. Press Ctrl+Shift+X (or click the extensions icon in the sidebar)
3. Search for “Python” and select the one from Microsoft (it has millions of downloads)
4. Click Install

Step 3: Select the Python interpreter

VSCode needs to know which version of Python to use:

1. Press Ctrl+Shift+P to open the command palette
2. Type “Python: Select Interpreter” and select it
3. Choose the version of Python you installed (you should see something like Python 3.12.x)

Step 4: Create your first project

Let’s organize your workspace:

1. Create a folder on your computer called python-course
2. In VSCode, go to File → Open Folder and select that folder
3. Create a new file: File → New File and save it as hello.py
4. Write the code from “Your first program” that we saw before
5. To run it, click the ▶️ button in the upper right corner, or press Ctrl+F5

Useful shortcuts

These shortcuts will save you a lot of time:

Practical Exercise

 1# Simple calculator
 2num1 = float(input("Enter the first number: "))
 3num2 = float(input("Enter the second number: "))
 4
 5print(f"Sum: {num1 + num2}")
 6print(f"Subtraction: {num1 - num2}")
 7print(f"Multiplication: {num1 * num2}")
 8
 9if num2 != 0:
10    print(f"Division: {num1 / num2}")
11else:
12    print("Cannot divide by zero")

Quiz

Test what you’ve learned:

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