Control formatting with `dump` / `dumps`

[alexreg]

Is there any way to control JSON5 aspects of formatting when using dump / dumps? For example, whether to quote key names of objects, or whether to include trailing commas.

[dpranke]

Yes, both of those things are supported, in fact :).

Unfortunately at the moment I don't have this lifted into obvious documentation (which I should fix), but if you look at the docstring for dumps:

https://github.com/dpranke/pyjson5/blob/main/json5/lib.py#L154

json5.dumps supports all of the args of json.dumps, plus three additional ones: allow_duplicate_keys, quote_keys, and trailing_commas. If you have other formatting options you'd like to see, I'm open to hearing about them :).

[alexreg]

Thanks for the quick reply, and I'm very glad to hear it's already implemented! For my current purposes, I believe those options suffice, though other ones I can imagine might be useful are:

• Separate options trailing_commas_array and trailing_commas_object (which trailing_commas could override).
• Allowing quote_keys to alternatively take a function of the key name, or possibly even a tuple of key names representing the current key within the JSON object hierarchy.

These would just be nice bonuses.

[dpranke]

It's a bit harder for me to picture trailing_commas_array or a conditional quote_keys to be useful: personally it feels like that would encourage stylistic inconsistencies. So, I wouldn't be inclined to add them just for the sake of things.

But, if someone comes up with convincing real-world examples of where they'd be useful, I could be convinced :).

[alexreg]

It was just me musing, but I agree it seems inconsistent (though I've observed separate settings for them elsewhere before.) As for quote_keys, I can imagine more situations where there might be a desire to customise that. Presumably already it falls back on quoting keys that have spaces in them. Oh, and I forgot — an option for using single vs. double quotes would also be handy.

[dpranke]

Yes, it should quote keys with spaces properly. I could imagine a single/double quote flag to be useful, though.