fast sub list operations

[Robin Becker]

In message <15308.11525.102304.624520 at beluga.mojam.com>, Skip Montanaro
<skip at pobox.com> writes
>
>
....
>
>I think most people will point you to NumPy.
>
>    Robin> ... I don't seem to have an interlace to get back to the original
>    Robin> list format.
>
>Check out the zip builtin function:
>
>    >>> zip([1,2,3],[7,8,9])
>    [(1, 7), (2, 8), (3, 9)]
>

I know about NumPy and like it a lot, but it's a bit heavyweight for
what we need. I also know about zip and apart from there being no unzip
it doesn't join up my list which should look like [1,7,2,8,3,9].
-- 
Robin Becker