Home Original page

[Python-Dev] PEP 457: Syntax For Positional-Only Parameters

Greg Ewing greg.ewing at canterbury.ac.nz
Thu Oct 10 04:33:16 CEST 2013 
On 10/10/13 09:51, Larry Hastings wrote:
> Perhaps we could add (egad, no, I can't believe I'm saying this) a new
> built-in function that tells you whether or not a local variable has been
> assigned to yet?
>
>     def range([start,] stop, [step], /):
>          if not bound(start):
>              start = 0
>          if not bound(step):
>              step = 1
>          ...

It couldn't be a function in the usual sense, because attempting to
evaluate the unbound parameter would raise an exception before the
function was called.

It would have to be something magical, probably a new piece of
syntax understood by the compiler.

-- 
Greg
More information about the Python-Dev mailing list