On 23 February 2012 22:04, Chris Angelico <ros...@gmail.com> wrote:
> On Fri, Feb 24, 2012 at 8:59 AM, Arnaud Delobelle <arno...@gmail.com> wrote:
>> def sum(iterable, start=_sentinel, _sentinel=_sentinel):
>
> Is this a reason for Python to introduce a new syntax, such as:
>
> def foo(blah, optional=del):
> if optional is del: print("No argument was provided")
>
> Basically, 'del' is treated like a unique non-providable object, only
> possible in an argument list and only if the argument was omitted. No
> more proliferation of individual sentinels... what do you think?
The problem with these proposals is to avoid the leakage of 'del'.
Here you could do:
def get_del(x=del):
return x
And then you're in trouble again.
--
Arnaud
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