keys and values lining up

[M.-A. Lemburg]

Guido van Rossum wrote:
> 
> Michael Haggerty <mhagger at blizzard.harvard.edu> writes:
> 
> > There's always
> >
> >     >>> d = {'key1' : 'val1', 'key2' : 'val2', 'key3' : 'val3'}
> >     >>> apply(map, [None] + d.items())
> >     [('key1', 'key2', 'key3'), ('val1', 'val2', 'val3')]
> >
> > if you have to go the items() route.
> 
> I don't know how well that will work for a really large dictionary,
> because all arguments get pushed on the stack (not the C stack, but
> still...).
> 
> But it's a really cool trick (by which I meant I hadn't tought of it
> :-).  Might be worth noting in the Python book of idioms.
> 
> Of course, if you have NumPy, there's always
> 
>         keys, values = transpose(d.items())
> 
> which probably beats everything else.

Or maybe the lists() and tuples() function in mxTools (available from my
Python Pages):

>>> d = {'key1' : 'val1', 'key2' : 'val2', 'key3' : 'val3'}
>>> import NewBuiltins # provided by mxTools
>>> lists(d.items())
(['key1', 'key2', 'key3'], ['val1', 'val2', 'val3'])
>>> tuples(d.items())
[('key1', 'key2', 'key3'), ('val1', 'val2', 'val3')]

depends on what you want to do with the result... (and yes
tuples() and lists() is written in C too).

-- 
Marc-Andre Lemburg
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