[Python-ideas] Adding rule about trailing comma.

[Andrew Barnert]

On Mar 30, 2015, at 23:35, INADA Naoki <songofacandy at gmail.com> wrote:
> 
> What about adding rule about trailing comma?

I don't understand the proposed rule from your example. Are you suggesting that a trailing comma be a syntax error unless it's following by a newline? That would explain both "yesses" and the first "no", but then what's wrong with the second "no"? You can always add newlines in the middle of any parenthesized expression; are you suggesting that you shouldn't be allowed to add one at the very end, unless it's immediately following a comma? If so, why?

Also, you seem to realize you're adding a gratuitous inconsistency with one-element tuples. Haven't they been through enough teasing without having to make them even more different?

Most of all, whatever your actual rule is: Why? What's the intended benefit here?

> 
> Yes:
> 
> foo(aaa,
>    bbb)
> 
> or
> 
> foo(aaa,
>    bbb,
> )
> 
> No:
> 
> foo(aaa,
>    bbb,)  # except one-value tuple.
> 
> or
> 
> foo(aaa,
>    bbb
> )
> 
> 
> 
> -- 
> INADA Naoki  <songofacandy at gmail.com>
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