In the latest episode of the Real Python Podcast the topic of Python Easter Eggs came up. One of the mentioned easter eggs was import __hello__:

>>> import __hello__
Hello World!
>>> import __phello__
Hello world!

There is even a spam version of it:

>>> import __phello__.spam
Hello world!
Hello world!

Batteries included

It makes sense that Python - the language with batteries included - also includes a hello world program, one import away right?

These top-level modules weren’t added just for fun, according to the comment in the CPython source code they were added for testing frozen modules:

/* In order to test the support for frozen modules, by default we
   define some simple frozen modules: __hello__, __phello__ (a package),
   and __phello__.spam.  Loading any will print some famous words... */

Python 3.11

In Python 3.11 the __hello__ and __phello__ modules no longer print the text when they are imported. You now have to call the module’s main method to get the same effect:

>>> import __hello__
>>> __hello__.main()
Hello World!
>>> import __phello__
>>> __phello__.main()
Hello World!

This isn’t the first time the __hello__ imports broke in a newer Python version. The same thing also happened in the initial versions of Python 3 (3.1, 3.2, 3.3, 3.4) according to this issue from 2011.

Even though the easter egg was fixed back in 2011, it looks like the change in Python 3.11 was intentional and won’t be reverted.