Regression: Importing __hello__ doesn't print "Hello world!"

[hugovk]

Bug report

Importing __hello__ or __phello__ on Python 3.7-3.10 prints "Hello world!"

Importing __hello__ or __phello__ on Python 3.11-3.12 prints nothing.

$ python3.7
Python 3.7.13 (default, Jul  8 2022, 20:05:46)
[Clang 13.1.6 (clang-1316.0.21.2.5)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import __hello__
Hello world!
>>> import __phello__
Hello world!
>>>

$ python3.8
Python 3.8.13 (default, Apr 26 2022, 16:12:31)
[Clang 13.1.6 (clang-1316.0.21.2.3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import __hello__
Hello world!
>>> import __phello__
Hello world!
>>>

$ python3.9
Python 3.9.13 (main, May 24 2022, 21:13:51)
[Clang 13.1.6 (clang-1316.0.21.2)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import __hello__
Hello world!
>>> import __phello__
Hello world!
>>>

$ python3.10
Python 3.10.6 (main, Aug 30 2022, 04:58:14) [Clang 13.1.6 (clang-1316.0.21.2.5)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import __hello__
Hello world!
>>> import __phello__
Hello world!
>>>

$ python3.11
Python 3.11.1 (v3.11.1:a7a450f84a, Dec  6 2022, 15:24:06) [Clang 13.0.0 (clang-1300.0.29.30)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import __hello__
>>> import __phello__
>>> ^D

$ python3.12
Python 3.12.0a3 (v3.12.0a3:b6bd7ffcbc, Dec  6 2022, 15:26:51) [Clang 13.0.0 (clang-1300.0.29.30)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import __hello__
>>> import __phello__
>>> ^D

And at least as early as 3.11.0a2:

$ ./python.exe
Python 3.11.0a2 (tags/v3.11.0a2:e2b4e4bab9, Dec  9 2022, 16:19:07) [Clang 14.0.0 (clang-1400.0.29.102)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import __phello__
>>> import __hello__
>>>

(I couldn't build 3.11.0a1)

Your environment

• CPython versions tested on: 3.7.13, 3.8.13, 3.9.13, 3.10.6, 3.11.0a2, 3.11.1, 3.12.0a3
• Operating system and architecture: macOS M1

[eryksun]

The behavior was intentionally changed by issue #89182 and pull request #28374. __hello__ and __phello__.spam still print to sys.stdout when run as scripts. When imported, main() has to be called. For example:

>>> import __hello__
>>> __hello__.main()
Hello world!
>>> import __phello__.spam
>>> __phello__.main()
Hello world!
>>> __phello__.spam.main()
Hello world!

[hugovk]

Okay, thanks.

I saw the old, short and simple version on a list of Python Easter eggs:

https://github.com/OrkoHunter/python-easter-eggs

And searching for Python Easter eggs it often shows up as the first one such as 'The Easiest “Hello World”':

• https://towardsdatascience.com/7-easter-eggs-in-python-7765dc15a203
• https://www.geeksforgeeks.org/top-5-easter-eggs-in-python/
• https://nolowiz.com/10-easter-eggs-in-python/
• https://blog.finxter.com/the-6-best-python-easter-eggs/
• https://www.alanzucconi.com/2015/10/29/the-top-5-easter-eggs-in-python/
• https://www.folkstalk.com/2022/10/python-easter-eggs-with-code-examples.html

It's less exciting in the new form.

But fine by me if you'd like to close this as correct behaviour.

[eryksun]

At least import this still prints the text of "The Zen of Python".

[zware]

How badly would it break the tests that depend on __hello__ to also call main() if sys.ps1 has a value? Is it worth saving the easter egg? :)