On Tue, 11 Nov 2014 20:43:01 +0000 (UTC) Denis McMahon <denismfmcma...@gmail.com> wrote:
> Hi > > Given x,y are a lists of keys and value that I wish to combine to a > dictionary, such that x[n] is the key for value y[n], which is preferred: > > z = {a:b for (a,b) in zip(x,y)} > z = {x[n]:y[n] for n in range(min(len(x),len(y)))} > > The zip feels more elegant, but it seems clunky to use the zip method to > create a list of tuples just to split them up into key:value pairs. > However the zip method handles the inequal length list problem. Granted > it would probably be advisable to check that x and y are the same length > before starting anyway. > > -- > Denis McMahon, denismfmcma...@gmail.com To add to what Gary said, the explicit dict() init knows how to handle an iterable that emits pairs of data. So you can simplify further down to: z = dict(zip(x, y)) If you're running Python2, and really that concerned about the extra memory used by zip returning a list rather than an iterator, you can use itertools.izip -- Rob Gaddi, Highland Technology -- www.highlandtechnology.com Email address domain is currently out of order. See above to fix. -- https://mail.python.org/mailman/listinfo/python-list