A couple comments.

1. Terry Reedy wrote:

> The csv expert listed in https://devguide.python.org/experts/ is marked as inactive

That would be me. I am indeed inactive w.r.t. fixing broken stuff, and
don't want to feel obligated to jump in with both feet when a CSV
ticket is raised. Still, I keep half an eye on things. If people are
actually interested in my opinion on such stuff, drop me a line.

2. Regarding the csv.Sniffer class... I've personally never found it
useful, and would be happy to see it deprecated. I occasionally define
a delimiter other than comma, and never specify the quotechar. (I've
never seen anything other than quotation marks used anyway.) As others
have indicated, the line terminator is kind of unnecessary with Python
3 (unless you need something really weird). If you actually need to
specify a delimiter, I think giving a set of candidate delimiters
would be sufficient. The first one encountered wins.

Maybe I'm just getting old and cranky, but deprecation is the fork in
the road I'd take, given the choice. Second choice would be to
simplify the delimiter sniffing logic and get rid of anything to do
with line terminators.

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