[Python-ideas] Before and after the colon in funciton defs.

[Adam Jorgensen]

It looks ugly and it's not so obvious what the : is associated with

-1

On 18 September 2011 22:58, Ron Adam <ron3200 at gmail.com> wrote:

> On Sun, 2011-09-18 at 15:32 -0400, Jim Jewett wrote:
> > On Sat, Sep 17, 2011 at 2:16 AM, Nick Coghlan <ncoghlan at gmail.com>
> wrote:
> >
> > > Specifically targeting existing uses of the default argument hack, on
> > > the other hand, comes with at least 3 already known use cases (i.e.
> > > name lookup micro-optimisation, early binding semantics and shared
> > > state for algorithms). People already tolerate messing with the
> > > function signature to obtain those behaviours, so it's reasonable to
> > > wonder if it is possible to provide a cleaner way to obtain the same
> > > effect. A simple set of definition time name bindings would likely
> > > suffice without greatly increasing the language complexity or the
> > > runtime overhead of function calls.
> >
> > Since the goal is to add some context, like a wrapper, it seems
> > reasonable to use a specialization of @.  @+ suggests adding something
> > to the environment, and won't be ambiguous unless numbers become
> > callable.
> >
> >     @+tuple=tuple
> >     @+sorted=sorted
> >     @+len=len
> >     @+KeyError=KeyError
> >     def decorating_function(user_function):
> >
> > I would personally be fine with a restriction to @+name=<expr> but I
> > suppose others might prefer a tuple, like
> >
> >
> >     @+(tuple, sorted, len, KeyError)=(tuple, sorted, len, KeyError)
> >     def decorating_function(user_function):
>
> If there was a method on a function object to set default values, then
> you could use a regular decorator.
>
>    # Most likely to live in functools
>
>    def preset(**kwds):
>        def apply(f):
>            f.set_default_values(kwds)
>            return f
>        return apply
>
>    #---------------------------------
>    from functools import preset
>
>    @preset(tuple=tuple, sorted=sorted, len=len, keyerror=keyerror)
>    def foo(...):
>        ...
>
> I was hoping there might be a more direct way to do it.  My previous
> idea breaks the white space consistency, and Nicks idea adds special
> syntax. Decorators with long arguments make the function name stand out
> less.
>
> Is there a more recent patch for Pep 362?
>
> Pep 362 seems to be targeted at only introspection and really isn't a
> part of the function object. Is that correct?
>
> Cheers,
>    Ron
>
>
>
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