Python: 'Hello, World!' Program

In this tutorial, you will learn to write and run your first 'Hello, World!' program in Python.

Python Shell

We first start the Python Shell in both MacOS and Linux systems.

Mac OS

Python comes pre-installed on Mac OS X. However, it is most likely the older 2.x version. You can check its version with the command: 

					
						$ python --version

To start the interactive shell for the Python interpreter, type python in the terminal and press ENTER. 

					
						$ python

This interactive shell is known as Python Shell. The interpreter is in interactive mode when the prompt consists of three greater-than signs (>>>), known as the Python REPL prompt. 

					
						Python 2.7.10 (default, Oct  6 2017, 22:29:07) 
						[GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.31)] on darwin
						Type "help", "copyright", "credits" or "license" for more information.
						>>>

If you have just typed that in your console and want to exit, type exit().

Or if you have downloaded and installed the updated version Python 3.x, you can also just type python3 in the terminal to start the updated shell. 

					
						$ python3

The prompt is ready to accept Python commands. 

					
						Python 3.7.0 (v3.7.0:1bf9cc5093, Jun 26 2018, 23:26:24) 
						[Clang 6.0 (clang-600.0.57)] on darwin
						Type "help", "copyright", "credits" or "license" for more information.
						>>>

We will make use of the Python function print() to print our 'Hello, World!' message. Type print('Hello, World!') and hit ENTER. The print() function is passed the string value 'Hello, World!', which is also known as an argument (a value which is passed to a function is called an argument). 

					
						>>> print('Hello, World!')

The print() function prints the string Hello, World! to the console.

python shell

Type exit() to quit the shell. 

					
						>>> exit()

Linux: Ubuntu/Debian

As in Mac OS, you type python3 in the terminal to start the Python Shell.

python shell ubuntu

IDLE's Python Shell

Python's IDLE (Integrated DeveLopment Environment) is both code editor and interactive interpreter combined.

In Mac OS, get to /Applications and expand the /Python 3.x directory

python idle

Python's IDLE is launched. You will see the interactive Python prompt >>>

idle python shell

Go to File > New File

python IDLE new file

and type print('Hello, World!') into the new unamed file.

python IDLE new program

Save the program with .py extension inside some directory. Here, I have saved it as hello.py inside the /python-programs directory.

python IDLE save program

To run our hello.py script, go to Run option and select Run Module (F5).

python IDLE run module

It will print the "Hello, World!" statement into the console.

python IDLE hello world

From the Command Line

Navigate to the /python-programs directory where the hello.py script file is located. Next run the below command. 

					
						$ python3 hello.py

Notes

  • REPL is short for Read-Eval-Print-Loop.