[Python-ideas] Positional only arguments

[Arnaud Delobelle]

On Sat, May 19, 2007 7:40 am, Steven Bethard wrote:
[...]
> So should I take that as a +1 for:
>
> * Enforce double-underscore names as being positional-only syntactically,
> e.g.::
>
>    def f(__a, __b=None, *, c=42, **kwargs)
>
>  Pro: requires no new syntax
>  Con: slightly backwards incompatible (but who calls f(__a) anyway?)
>


- There is also incompatibility in the definition of functions: 'def f(a,
__b)' is currently correct, it wouldn't be anymore.

- How would this work with name mangling and methods?  For example:

class Foo(object):
    def posfun(__self, __a, b, ...):

* Would self have to be renamed __self? (As positional only arguments
should come first)

* Would __self and __a be mangled, as is the rule within classes up to
now?  If so care has to be taken I suppose.

-- 
Arnaud