[documentation/typing request] what are allowed values for compress?

[bddap]

The compress parameter currently has type Union[str, bool]. It’s clear that False and True are valid, but the documentation doesn’t specify which string values are acceptable.

• "gzip" appears to work and properly switches the request from deflate to gzip.
• "some rando string" doesn’t raise an exception, which is unexpected.
• The docs don’t mention passing a string at all (and they have a small grammar issue too). The docs also seem out of date regarding None, which no longer appears to be valid in the current main branch.

It would be great to:

1. Use something like typing.Literal["gzip", ...] in place of str, so users know which strings are valid.
2. Outline these allowed string values in the client documentation.

Appreciate the python package btw. It has been useful.

[Dreamsorcerer]

As far as I can see in the code, it just sets the mode for zlib:

aiohttp/aiohttp/compression_utils.py

Lines 27 to 34 in e507ba3

	def encoding_to_mode(
	encoding: Optional[str] = None,
	suppress_deflate_header: bool = False,
	) -> int:
	if encoding == "gzip":
	return 16 + zlib.MAX_WBITS
	return -zlib.MAX_WBITS if suppress_deflate_header else zlib.MAX_WBITS

In which case, yes it's just gzip, deflate/True or False.

[Dreamsorcerer]

I'm not really familiar with the reason it's designed like that though, so maybe someone else has some idea of whether it might be expanded in future or something..