referencing disjoint array indexes

[Stuart D. Gathman]

On Mon, 11 Nov 2002 07:28:19 -0500, Padraig Brady wrote:


> Is there any way you can do something like
> 
> size, mtime = os.stat()[8,6]

def index(seq,il):
    res = [seq[i] for i in il]
    if type(seq) == str:
      return ''.join(res)
    if type(seq) == tuple:
      return tuple(res)
    return res

size, mtime = index(os.stat(),[8,6])

I proposed the very intuitive syntax you suggest earlier in this group,
and was informed that additional semantic overlays to indexing were Not Welcome
- especially when a function does the trick.

However, a pure python implementation of the index function suffers from
having to copy a list to a tuple.  A C version could build the tuple or
string directly - even if still using the function syntax.  In your application,
the improvement would be negligible.

The seq[list] notation is particularly natural to me having used APL once
upon a time.

-- 
	      Stuart D. Gathman <stuart at bmsi.com>
Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703 591-6154
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