inspect feature

[George Sakkis]

On Oct 14, 5:00 pm, "Aaron \"Castironpi\" Brady"
<castiro... at gmail.com> wrote:
> On Oct 14, 2:32 pm, George Sakkis <george.sak... at gmail.com> wrote:
>
>
>
> > On Oct 14, 2:35 pm, "Aaron \"Castironpi\" Brady"
>
> > <castiro... at gmail.com> wrote:
> > > On Oct 14, 9:42 am, George Sakkis <george.sak... at gmail.com> wrote:
>
> > > > On Oct 14, 3:06 am, "Gabriel Genellina" <gagsl-... at yahoo.com.ar>
> > > > wrote:
>
> > > > > En Fri, 10 Oct 2008 14:18:53 -0300, Aaron "Castironpi" Brady
> > > > > <castiro... at gmail.com> escribió:
>
> snip
> > > > > > You are wrapping a function with this signature:
>
> > > > > > def f( a, b, c= None, *d, **e ):
>
> > > > > > You want to find out the values of 'a', 'b', and 'c' in a decorator.
> > > > > > You have these calls:
>
> > > > > > f( 0, 1, 'abc', 'def', h= 'ghi' )
> > > > > > f( 0, 1 )
> > > > > > f( 0, 1, h= 'abc' )
> > > > > > f( 0, 1, 'abc', c= 'def' ) #raise TypeError: multiple values
>
> > > > > > How do you determine 'a', 'b', and 'c'?
>
> > > > > I'm afraid you'll have to duplicate the logic described here:  http://docs.python.org/reference/expressions.html#id9
> > > > > To my knowledge, there is no available Python code (in the stdlib or
> > > > > something) that already does that.
>
> > > > I wrote such a beast some time ago; it's hairy but to the best of my
> > > > knowledge it seems to reproduce the standard Python logic:http://code.activestate.com/recipes/551779/
>
> > > > George
>
> > > I didn't see a 'got a duplicate argument for keyword "d"' error, but I
> > > can add one if I need to.
>
> > Why don't you try it out:
>
> > >>> def f( a, b, c= None, *d, **e ): pass
> > >>> getcallargs(f, 0, 1, 'abc', c= 'def' )
>
> > Traceback (most recent call last):
> >   File "<stdin>", line 1, in <module>
> >   File "getcallargs.py", line 53, in getcallargs
> >     "argument '%s'" % (f_name,arg))
> > TypeError: f() got multiple values for keyword argument 'c'
>
> > George
>
> Excellent.
>
> Here's some more info.
>
> Ver 2.5:
>
> >>> f( c= 0, c= 0 )
>
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> TypeError: f() got multiple values for keyword argument 'c'>>> getcallargs( f, c= 0, c= 0 )
>
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
>   File "<stdin>", line 64, in getcallargs
> TypeError: f() takes at least 2 non-keyword  arguments (0 given)
>
> Just the wrong order to check errors in.

The problem is getcallargs doesn't even see the double entry; if you
print (args, kwds) from within getcallargs you get ((), {'c': 0}). The
SyntaxError raised in 2.6 is more reasonable.

George