On 11/11/2014 12:43 PM, Denis McMahon 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.
Are you using python 2 or 3. (It ought to be 3 :-) .)
In Python3, zip does not create a list, but rather an iterator which
returns tuples. Not clunky at all, but rather an efficient
implementation of the loop which you hand coded in your other example.
From help(zip):
class zip(object)
| zip(iter1 [,iter2 [...]]) --> zip object
|
| Return a zip object whose .__next__() method returns a tuple where
| the i-th element comes from the i-th iterable argument. The
.__next__()
| method continues until the shortest iterable in the argument sequence
| is exhausted and then it raises StopIteration.
...
Gary Herron
--
Dr. Gary Herron
Department of Computer Science
DigiPen Institute of Technology
(425) 895-4418
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