On 12/12/2014 06:22, KK Sasa wrote:
Hi there,
The list comprehension is results = [d2(t[k]) for k in xrange(1000)], where d2 is a
function returning a list, say [x1,x2,x3,x4] for one example. So "results" is a
list consisting of 1000 lists, each of length four. Here, what I want to get is the sum
of 1000 lists, and then the result is a list of length four. Is there any efficient way
to do this? Because I found it is slow in my case. I tried sum(d2(t[k]) for k in
xrange(1000)), but it returned error: TypeError: unsupported operand type(s) for +: 'int'
and 'list'. Thanks.
I think you need something like this
http://stackoverflow.com/questions/19339/a-transpose-unzip-function-in-python-inverse-of-zip
I'll let you add the finishing touches if I'm correct :)
--
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what you can do for our language.
Mark Lawrence
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