[Python-ideas] Positional only arguments

Aaron Brady castironpi at comcast.net
Tue May 22 11:45:01 CEST 2007

> -----Original Message-----
> From: python-ideas-bounces at python.org [mailto:python-ideas-
> bounces at python.org] On Behalf Of Ron Adam
>     def f(; a, b=2, c=3;):  No positional only, no keyword only

Do you prohibit defaults in type 1, the pos-only?

Not necc.  Does this look right?

>>> def f( a=0; b=1 ):
...	print a, b
>>> f()
0, 1

Also, does this look right?

>>> def f( a=0; b ):
...	print a, b
  File "<stdin>", line 1
SyntaxError: non-default argument follows default argument

Any more groups?  So far I have pos-only, pos-or-kw, and kw-only.

If not, a ascii character works fine to delimit, like * and **.

Do we want to annotate each parameter individually?  This could get out of
hand.  But decorators won't let you do

@f( k )
	def j( k ):


@f( 'k' )
	def j( k ):

gets unwieldy and could show promise.  Cf. Steven's positional only
arguments decorator.

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