I personally love Python where whitespace matters a lot too. But I regularly find myself fighting with the whitespace in yaml for some reason.

To me yaml (especially with templating) seems like a very contrived way of avoiding having to program, while still effectively programming. I much prefer json, or if more intelligence is required, actual javascript objects.

The only big downside of json where yaml does shine is the support for comments within your files.

White space matters with Python but I rarely run into issues with indentation in Python. But YAML on the other hand, I have nothing but nightmares.

I have the same experience. I just think think it is possible to design easy-to-write indentation-sensitive formats but YAML is not. For example is always baffles me that

    a:
    - b
    - c

has a list inside an object but the list is not further indented. There's in fact a hierarchy relationship but absolutely no indentation.

You can indent it though, but the hyphen already means a list item.

That is a preferred syntax for many that are used to YAML though.

The hyphen is associated with the a though. In what's posted, a is a list, not a map - the type of the parent is being declared by that hyphen.

That's kind of my point. Indentation is optional, so many don't indent, making the resulting document harder to understand.

FWIW, I think yaml / ansible linters and style checkers typically require indentation.

That's at your option, though. It's perfectly valid yaml to indent the list as many spaces as you want.

I think its because python has very strict and very simple indentation rules (a nested block must be indented, and the file requires consistent indentation. Is there anything else?)

YAML gives you options, or varies necessity somewhat arbitrarily on the structures, which is (marginally) good for reading, but a lot of headache in writing

Also because the longer the YAML file, the bigger your indentation gets. It gets exponentially worse as you go.

In python that’s been a non-issue, but I’m not sure YAML can reset indentation as python does with functions

I never quite understood this attitude. Not treating whitespace as meaningful means it's necessary to have a longer, syntactically noisier file.

That's fine if you're primarily concerned with computers exchanging data (JSON) but where readability and writability matters, extra syntactic weight is a headache.

I can't imagine writing JSON by hand but I write plenty of YAML by hand every day without issues.

Because deleting a tab could entirely change the meaning of the file, breaking everything, with no compile time errors. IDE tooling or linting might go somewhat to make me more comfortable with YAML.

> I don't like any language or file format where whitespace matters. .... To me white space shouldn't add cognitive load.

1. there is no language where whitespace does not matter

2. the very purpose of indentation is to ease cognitive load.

Now, you may not want it to be inflexible or mandatory but your argument needs elucidating.

Ok: I don't like any language of file format where the regex s/\s+/\s/g would change the meaning of the program except in parts of the program within string delimiters, except for the parts of string delimiters which contain literal code e.g. ins ES6 `Hello ${world}`.

So you prefer languages way that regex only appears to change the meaning?

Non-semantic white space can be deceptive. Semantic whitespace isn't.

OK, but I'd restrict the set even more to exclude voluntary indentation. I mean, you'd want that caught by style checkers anyway, even if the language didn't require it.

So we're left with the cases where you'd like compact code / one-liners but are forced to use multiple lines for language syntax reasons.

I'd say that that's a pretty small set of cases and long way from the phrase "I don't like whitespace sensitive languages" which you (and many others!) use.

I conceded it can be annoying in Python and I do wish there was an escape route sometimes.

Experienced programmers use decent editors to indent their code anyway but at least you don't see codes with indentation going left and right at random locations with Python.