[Python-Dev] A grammatical oddity: trailing commas in argument lists -- continuation

[Ethan Furman]

Terry Reedy wrote:
> On 12/13/2010 2:17 PM, Antoine Pitrou wrote:
>> On Mon, 13 Dec 2010 14:09:02 -0500
>> Alexander Belopolsky<alexander.belopolsky at gmail.com>  wrote:
>>
>>> On Mon, Dec 13, 2010 at 11:54 AM, Guido van Rossum<guido at python.org>  
>>> wrote:
>>>> I'm at least +0 on
>>>> allowing trailing commas in the situation the OP mentioned.
>>>>
>>>
>>> FWIW, I am also about +0.5 on allowing trailing comma.  Note that in a
>>> similar situation,  the C standardization committee has erred on the
>>> side of consistency:
>>>
>>> """
>>> A new feature of C99: a common extension in many implementations
>>> allows a trailing comma after the list of enumeration constants. The
>>> Committee decided to adopt this feature as an innocuous extension that
>>> mirrors the trailing commas allowed in initializers.
>>> """ http://www.open-std.org/jtc1/sc22/wg14/www/C99RationaleV5.10.pdf
>>>
>>> Similarly, I find allowing trailing comma in keyword only arguments
>>> lists to be an innocuous extension that mirrors the trailing commas
>>> allowed in the positional arguments lists.
>>
>> +1 from me as well. Special cases are hard to remember.
> 
> Same here. A strong +1 for a consistent rule (always or never allowed) 
> with a +1 for always given others use case of one param/arg per line.

+1 on consistency.

+1 on allowing the trailing comma.

~Ethan~