F-strings:
For most cases, f-strings are the best choice. They're concise, readable, and performant.

.format() method:
If you need to support older Python versions or want more complex formatting options, use .format().

Old-style % formatting:
Avoid this method for new code, but be able to recognize it in legacy code.

Skill issue?

But yes, this would be a lot easier if the method/function took an int array as input. But then this kata would be even easier and not as fun.

kept trying with int as input -_-

No, I mean you are using the max and min functions on a list of strings. The way you sort a list of strings is different form how you sort a list of numbers.

See: https://www.codewars.com/kata/554b4ac871d6813a03000035/discuss#60cb692f9c75d0003d7b9a79

This is python.

Yes, the instruction asked to return a string of numbers separated by a single space

Even after moving the logic out of the loop, it still gives same test error

Which programming language is this?

The issue is definitely your code, and my first guess is that you are sorting a list of strings, instead of a list of numbers.

Other than that, you are doing things in a loop for some reason, so you are finding the highest and lowest values multiple times.

The tests are fine in javascript, it's your code that's returning the wrong answer:

expected '8 -1' to equal '42 -9' <- expected answer
            ^
        your answer

Not a kata issue.

Which programming language? And what was the exact output of the failed test case?

I highly doubt there is an issue though, unless this is a very recently added translation. Since this kata has thousands of completions.

the tests do not work correctly. they do not return the highest and lowest. like in this case: [
'8', '3', '-5', '42',
'-1', '0', '0', '-9',
'4', '7', '4', '-4'
], it expected '8 -1'.

The Description has been changed, so you need to somehow pull from master? Not completely sure how that is done here.

Also need you to add an example to the Description. But I can add it myself if it is.

Looks good.

I am just sad you didn't post as a comment on the kata so I had noticed this sooner.

You need to actually return the result, not print it.

Your solution is not exactly correct. See this article for related info: https://docs.codewars.com/training/training-example#writing-a-solution