Crumb
c/python · by qwop@programming.dev · 3y

Python 2 in Python 3!

A post about how this community's banner used the python 2 print syntax - print "Hello World" - made me question, can we print a hello world message in Python 3 without using parentheses?

It turned out to be sort of a fun challenge, I've found 3 different approaches that work. I'd be interested to see what you come up with! (it seems I can't put spoilers in Lemmy, so I won't share my solutions yet in case y'all want to have a go).

Edit: Posted my solutions in the comments

20 points · 12 comments · view on lemmy.world

12 Comments

jsalvador@programming.dev · 6 pts · 3y

Just one question: why?

sisyphean@programming.dev · 5 pts · 3y (3 replies)

You can put spoilers in posts or comments this way:

::: spoiler Title
Secret
:::

Here is how it renders:

::: spoiler Title Secret :::

(AFAIK apps don't render these correctly, only the website)

nydas@lemmy.world · 6 pts · 3y (2 replies)

Can confirm not hiding on Memmy

Pabo@feddit.nl · 5 pts · 3y (1 reply)

Same on Jerboa. Though given the apps' fast development progress we probably won't have to wait too long :)

pythonoob@programming.dev · 1 pts · 3y

Not working on connect either

jormaig@programming.dev · 3 pts · 3y (3 replies)

You could base64 encode the solution

McCheng@lemmy.fmhy.ml · 3 pts · 3y (2 replies)

But then you still need to use parentheses to decode it

jormaig@programming.dev · 2 pts · 3y (1 reply)

Ah sorry I meant for the spoiler. He could base64 the solution given that he doesn't know how to do spoilers on lemmy

qwop@programming.dev · 1 pts · 3y

Ah true that would have worked, figured since spoilers don't work on most apps I might as well just post them.

McCheng@lemmy.fmhy.ml · 2 pts · 3y (2 replies)

Gave some thoughts but couldn't find any. I need the solutions

qwop@programming.dev · 7 pts · 3y (1 reply)

Alright, here are my solutions :)

  1. Import Easter egg
import __hello__

Not the most technically interesting, but a fun Easter egg!

  1. Class decorators
@print
@lambda _: "Hello World"
class Foo: 
    ...

Decorators are another way of calling a function, so can be abused to solve this task. You need to decorate a class rather than a function though, since a function definition requires parentheses!

  1. Dunder methods
class Printer:
    __class_getitem__ = print

Printer["Hello World"]

There might be some other Dunder methods you can use to do this, although it's sort of difficult since most (e.g. __add__) only describe behaviour on the instance of the class.

  1. More dunder methods
from _sitebuiltins import Quitter
Quitter.__add__ = print
exit + "Hello World"

Writing number 3 made me realise I just needed to find a class that already had an instance and change that. I'm sure there are many other cases of this, but here's one!

McCheng@lemmy.fmhy.ml · 1 pts · 3y

Very interesting solutions. I was in the direction of using dunder methods but could not figure out how. Haven't heard of the __class_getitem__. The second solution is especially inspiring.