Python Hello World

Summary: in this tutorial, you’ll learn how to develop the first program in Python called “Hello, World!”. 

If you can write “hello world” you can change the world.

Raghu Venkatesh

Creating a new Python project

First, create a new directory called helloworld anywhere in your system e.g., C:\ drive.

Second, launch the VS code and open the helloworld directory.

Third, create a new app.py file, enter the following code, and save it:

print('Hello, World!')Code language: Python (python)

The print() is a built-in function that displays a message on the screen. In this example, it’ll show the message 'Hello, Word!'.

What is a function

When you sum two numbers, that’s a function. And when you multiply two numbers, that’s also a function. In general, a function takes your inputs, applies some rules, and returns a result.

In the above example, the print() is a function. It accepts a string and shows it on the screen.

Python has many built-in functions like the print() function to use them out of the box in your program.

In addition, Python allows you to define your functions, which you’ll learn how to do it later.

Executing the Python Hello World program

To execute the app.py file, you first launch the Command Prompt on Windows or Terminal on macOS or Linux.

Then, navigate to the helloworld directory.

After that, type the following command to execute the app.py file:

python app.pyCode language: Python (python)

If you use macOS or Linux, you use python3 command instead:

python3 app.pyCode language: CSS (css)

If everything is fine, you’ll see the following message on the screen:

Hello, World!Code language: Python (python)

If you use VS Code, you can also launch the Terminal within the VS code by:

• Accessing the menu Terminal > New Terminal
• Or using the keyboard shortcut Ctrl+Shift+`.

Typically, the backtick key (`) located under the Esc key on the keyboard.

Python IDLE

Python IDLE is the Python Integration Development  Environment (IDE) that comes with the Python distribution by default.

The Python IDLE is also known as an interactive interpreter. It has many features such as:

• Code editing with syntax highlighting
• Smart indenting
• And auto-completion

In short, the Python IDLE helps you experiment with Python quickly in a trial-and-error manner.

The following shows you step by step how to launch the Python IDLE and use it to execute the Python code:

First, launch the Python IDLE program:

A new Python Shell window will display as follows:

Now, you can enter the Python code after the cursor >>> and press Enter to execute it.

For example, you can type the code print('Hello, World!') and press Enter, you’ll see the message Hello, World! immediately on the screen:

Summary

• Use the python app.py command from the Command Prompt on Windows or Terminal on macOS or Linux to execute the app.py file.
• Use the print() function to show a message on the screen.
• Use the Python IDLE to type Python code and execute it immediately.