2025 Introduction to Python and Installation

Q: 3. How do I check if Python is installed?

Use the command python --version or python3 --version in the terminal or command prompt.

2025 Introduction to Python and Installation –

Python is one of the most popular programming languages in the world. It is widely used for web development, data analysis, artificial intelligence, and many other areas.

Python is known for its simple and readable syntax, which makes it beginner-friendly. Whether you are a student, a professional, or just curious about coding, Python is a great language to start with.

What is Python?

Python is a high-level, interpreted programming language created by Guido van Rossum and first released in 1991. It is open-source and has a large community of developers who contribute to its growth. Python’s design emphasizes code readability, allowing developers to write clear and concise programs.

Python is used in various fields, including:

Web Development: Frameworks like Django and Flask help in building web applications.
Data Science: Libraries like Pandas, NumPy, and Matplotlib assist in data analysis and visualization.
Artificial Intelligence (AI) and Machine Learning (ML): TensorFlow and PyTorch are popular libraries for AI and ML.
Automation: Python can automate repetitive tasks, saving time and effort.
Game Development: Pygame is a library for creating simple games.

Why Learn Python?

Easy to Learn: Python has a simple syntax similar to plain English, making it easier to understand.
Versatile: It can be used for a wide range of applications, from web development to data science.
Community Support: Python has a vast and active community, providing extensive resources and help.
Job Opportunities: Python developers are in high demand across various industries.
Open Source: It is free to use and distribute.

Prerequisites for Installing Python

Before you install Python, ensure that your computer meets the following requirements:

Operating System: Python is compatible with Windows, macOS, and Linux.
Storage Space: Ensure you have at least 100 MB of free space.
Internet Connection: Required to download Python and additional packages.

How to Install Python

Follow these steps to install Python on your system.

1. Installing Python on Windows

Step 1: Download Python

Go to the official Python website: https://www.python.org/downloads/
Click on the “Download Python” button. The website automatically suggests the best version for your system.

Step 2: Run the Installer

Open the downloaded file.
Check the box that says “Add Python to PATH” to make Python accessible from the command line.
Click “Install Now” to begin the installation.

Step 3: Verify Installation

Open Command Prompt (Win + R, type “cmd”).
Type python --version and press Enter.
If Python is installed correctly, the version number will be displayed.

2. Installing Python on macOS

Step 1: Download Python

Visit https://www.python.org/downloads/
Download the latest macOS installer.

Step 2: Run the Installer

Open the downloaded file and follow the installation prompts.
Ensure the installer adds Python to your system PATH.

Step 3: Verify Installation

Open Terminal (Cmd + Space, type “Terminal”).
Type python3 --version and press Enter.
If installed correctly, the Python version appears.

3. Installing Python on Linux

Step 1: Update Package List

Open Terminal.
Type the following command and press Enter:

sudo apt update

Step 2: Install Python

Use this command to install Python:

sudo apt install python3

Step 3: Verify Installation

Check if Python is installed using:

python3 --version

Setting Up a Python Environment

After installation, it is a good practice to create a virtual environment. This helps manage different Python projects with separate dependencies.

Step 1: Install Virtual Environment Package

pip install virtualenv

Step 2: Create a Virtual Environment

python3 -m venv myenv

Step 3: Activate Virtual Environment

On Windows:

myenv\Scripts\activate

On macOS/Linux:

source myenv/bin/activate

source myenv/bin/activate

Adding Python to Environment Variables (PATH)

If Python is not recognized in your terminal, you may need to manually add it to your system’s PATH.

Open “Control Panel” > “System” > “Advanced system settings”.
Click on “Environment Variables”.
Find and select “Path” under “System variables”.
Click “Edit” and add the directory where Python is installed (e.g., C:\PythonXX and C:\PythonXX\Scripts).
Click “OK” to save.

Writing Your First Python Program

Let’s write a simple program to print “Hello, World!”.

Step 1: Open your preferred code editor (e.g., VSCode, Notepad++, or any text editor).

Step 2: Write the following code:

print("Hello, World!")

Step 3: Save the file as hello.py.

Step 4: Run the Program

Open the terminal or command prompt.
Navigate to the directory where hello.py is saved.
Type the following command:

python hello.py

You should see:

Hello, World!

Common Python Commands

Here are a few essential Python commands:

print() – Outputs text to the screen.
input() – Takes user input.
len() – Returns the length of a string or collection.
type() – Checks the data type of a variable.
import – Imports external libraries.

Troubleshooting Python Installation Issues

Command Not Recognized:
- Ensure Python is added to the system PATH.
Permission Errors:
- Use administrative privileges during installation.
Version Conflicts:
- Use virtual environments to manage different Python versions.