Python allows programmers to pass additional arguments to functions via comments. Now armed with this knowledge head out and spread it to all code bases.

Feel free to use the code I wrote in your projects.

Link to the source code: https://github.com/raldone01/python_lessons_py/blob/v2.0.0/lesson_0_comments.ipynb

Image transcription:

# First we have to import comment_arguments from arglib
# Sadly arglib is not yet a standard library.
from arglib import comment_arguments


def add(*args, **kwargs):
    c_args, c_kwargs = comment_arguments()
    return sum([int(i) for i in args + c_args])


# Go ahead and change the comments.
# See how they are used as arguments.

result = add()  # 1, 2
print(result)
# comment arguments can be combined with normal function arguments
result = add(1, 2)  # 3, 4
print(result)

Output:

3
10

This is version v2.0.0 of the post: https://github.com/raldone01/python_lessons_py/tree/v2.0.0

Note:

v1.0.0 of the post can be found here: https://github.com/raldone01/python_lessons_py/tree/v1.0.0

Choosing lib as the name for my module was a bit devious. I did it because I thought if I am creating something cursed why not go all the way?

Regarding misinformation:

I thought simply posting this in programmer humor was enough. Anyways, the techniques shown here are not yet regarded best practice. Decide carefully if you want to apply the shown concepts in your own code bases.

    • Doxin@pawb.social
      1·
      10 hours ago

      Because whoever wrote this went to great lengths to make it work. It’s by no means a feature of python. It’s a feature of their code.

  • would_be_appreciated@lemmy.mlEnglish
    0·
    5 days ago

    I assume the people freaking out about how dumb python is didn’t bother to read the code and have never coded in python in their life, because the behavior here is totally reasonable. Python doesn’t parse comments normally, which is what you’d expect, but if you tell it to read the raw source code and then parse the raw source code for the comments specifically, of course it does.

    You would never, ever accidentally do this.

    …you’d also never, ever do it on purpose.

    • Swedneck@discuss.tchncs.de
      0·
      4 days ago

      yeah frankly this post is borderline misinformation, they specifically import a library to read comments as arguments, it’s like redefining keywords in C and complaining about C being dumb

        • bastion@feddit.nl
          0·
          3 days ago

          Yeah. ‘lib’ isn’t a standard Python library, it’s the name of the abomination that this person created. Since python has quite a bit of useful introspection, they can do something like:

          • get the stack
          • find the exact call to abomination.add()
          • reparse the text of that line, turn the text of the comment into actual numbers, and add them

          Now, I don’t know if python keeps the comments around, so it may involve getting the filename and line number, reading the file, and manually extracting the comment text from that line.

          • CanadaPlus@lemmy.sdf.org
            0·
            3 days ago

            It’s not even actually called lib. The line just straight up isn’t in the image “transcribed”, and it’s from arglib import comment_arguments in the original code.

            Yeah, I gave this one a downvote.

            • raldone01@lemmy.worldOPEnglish
              1·
              8 hours ago

              I updated the source after this post was made. The image transcription still holds. I did not update the image and the post text.

              You can view the git history. I will tag the specific commit at the time of the post later and update it accordingly.

  • davel@lemmy.mlEnglish
    0·
    5 days ago

    What? There is no lib module.

    $ python3.13 -c 'import lib'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
    import lib
ModuleNotFoundError: No module named 'lib'
$
      • raldone01@lemmy.worldOPEnglish
        1·
        8 hours ago

        Yeah. This post was made to show off something cursed I created.

        I have already updated the repo to make it more obvious this is not standard Python. I will do the same with the post.

  • bdonvr@thelemmy.club
    0·
    5 days ago

    IMO comments should never ever be parsed under any circumstances but I probably don’t know enough to really speak on this

    • jaxxed@lemmy.world
      0·
      3 days ago

      Can we just clarify that you mean that comments should never be parsed by the language engine. There are valid annotation systems, but the goal is alway to ensure that one passable can never impact the other.

      Imagine if here a comment could create a syntax error! This is even worse for runtime scripting languages like python.

      • bastion@feddit.nl
        0·
        3 days ago

        Sure, but let’s just clarify that this is someone going out of their way to create this problem, using Python’s ability to read it’s own code.

        Basically, you can load any text file, including a source code file, and do whatever you want with it.

        So, a function can be written that finds out whatever’s calling it, reads that file, parses the comments, and uses them as values. This can also be done with introspection, using the same mechanism that displays tracebacks.

      • raldone01@lemmy.worldOPEnglish
        1·
        8 hours ago

        Well now that causes breakage two dependencies down the line. Good luck with that. 😅

        • raldone01@lemmy.worldOPEnglish
          1·
          8 hours ago

          On a serious note:

          This feature is actually very useful. Libraries can use it create neat error messages. It is also needed when logging information to a file.

          You should however never ever parse the source code and react to it differently.