On Wed, 20 May 2015 at 06:27AM +0800, Huayi Wei wrote:
> Hi, everyone,
>
> I want to create a sparse matrix, so I need to create a dict first.
> I try to use `dict.fromkeys()` to do it, which like following:
>
> ```
> sage: keys = [(0,1),(1,2)] # the length of keys maybe very long
> sage: values = [0,1] # values have the same length as keys
> sage: d = dict.fromkeys(keys,values)
> sage: d
> {(0, 1): [0, 1], (1, 2): [0, 1]}
> ```
> But the result is not what I want, and I want to get this:
>
> ```
> {(0,1):0,(1,2):1}
> ```
>
> Does there exist other way to do this? Hope to get your help, thanks
> very much.
Try just "dict()":
dict(zip(keys, values))
{(0, 1): 0, (1, 2): 1}
Here's how zip() works, if you don't already know:
https://docs.python.org/3.5/library/functions.html#zip
Dan
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--- Dan Drake
----- www.math.wisc.edu/~ddrake/
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