[Python-Dev] A grammatical oddity: trailing commas in argument lists. (original) (raw)

Eric Smith eric at trueblade.com
Fri Jul 9 18:36:01 CEST 2010


On 7/9/10 10:40 AM, Mark Dickinson wrote:

While looking at a parser module issue (http://bugs.python.org/issue9154) I noticed that Python's grammar doesn't permit trailing commas after keyword-only args. That is,

def f(a, b,): pass is valid syntax, while def f(*, a, b,): pass is not. I was just curious whether the latter was deliberate or an oversight. And if an oversight, is it worth fixing after the moratorium expires? (See also http://bugs.python.org/issue2009.)

I use trailing commas all the time in argument lists. I don't use keyword-only args much, but I will when I switch to 3.x. I'd like to see this fixed. I'd argue it's a bug fix, but that's me.

-- Eric.



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