OK, here's a patch for _csv.  Two problems here:

First problem is the __new__ method of the Dialect class:

* it has no docstring and no methoddef entry
* it is a class method, but the first arg is conventionally called "type"

I tried to hack something into clinic with a new decorator, but it may not be how you want it to look, take care.

Second problem is the functions reader(), writer(), register_dialect(): they parse their *args but pass their **kwargs through to another class.
Is there anything like a "**kwds" argument specifier?

BTW, for a module like _csv that is exported through a Python module named csv, should we use the "real" or the "nice" module name?