[Python-Dev] trailing commas on statements

[Chris Angelico]

On Wed, Aug 12, 2015 at 3:01 AM, R. David Murray <rdmurray at bitdance.com> wrote:
> Sorry, "trailing comma outside ()" was a shorthand for 'trailing comma
> on a complete statement'.  That is, what trips me up is going from
> something like:
>
>     dict(abc=1,
>          foo=2,
>          bar=3,
>          )
>
> to:
>
>       abc = 1,
>       foo = 2,
>       bar = 3,
>
> That is, I got rid of the dict(), but forgot to delete the commas.
> (Real world examples are more complex and it is often that the
> transformation gets done piecemeal and/or via cut and paste and I only
> miss one or two of the commas...
>
> But, for backward compatibility reasons, we wouldn't change it even if
> everyone thought it was a good idea for some reason :)

Sure. In that case, I agree with you completely. When I *do* want a
tuple, I'll usually be putting it inside parens, rather than just
tagging a comma on. But this can be the job of a linter.

ChrisA