[Python-3000] PEP 3102

[Georg Brandl]

Dj Gilcrease schrieb:
> On Fri, Feb 15, 2008 at 8:46 AM, Joel Bender <jjb5 at cornell.edu> wrote:
>>  How about a BNFish notation?  Use brackets around optional parameters.
>>
>>      def test([arg1, [arg2,]] arg3):
>>          ...
> 
> If I understand right, positional only arguments would not be optional
> in any way shape or form, thats what default arguments are for.
> Positional only args would be arguments that you cannot specify by
> keyword, so having a positional only arg that has a default value,
> thus making it optional just seems broken to me.

Being positional-only and having a default value does not conflict.
There's nothing at all broken with

def foo(!x, !y='bar'):
     pass

where !x and !y would be positional-only arguments. You can't of course
have something like

def foo(!x, !y='bar', z):
     pass

but you can't have that today either.

Georg

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