[Python-ideas] dictionary unpacking

Aaron Watters aaron.watters at gmail.com
Wed Apr 2 17:16:50 CEST 2008

"Facundo Batista" <facundobatista at gmail.com>
>bar, spam = d.multiple("foo", "egg")

Terry Reed:
->1 because the need is way to rare for new syntax support and because

|  bar, spam = [d[k] for k in ("foo", "egg")]

>already does what is wanted in easily understood code.

This is true, but with a fast implementation this
operation is incredibly useful.  If we go waaay back
to kjbuckets (the original "set" module circa 1993 or so)
there was

(v1,v2,v3) = D.dump( (k1,k2,k3))

and also the inverse operation

kjDict.undump( (k1,k2,k3), (v1, v2, v3) )

which are extremely useful for packing/unpacking
large data structures.

Please see

There are lots of other cool operations which
can be very handy -- transpose, difference, closure...

By the way, I've been delighted to see Python
gradually growing features that kjbuckets provided
more than a decade ago.  It's just too bad you
guys can't figure out how to get them all at once

   -- Aaron Watters

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