computing a weighted sum

[andreif]

Suppose I have a list of n floats x and a list of n floats w and I want
to compute x[0]*w[0] + .. + x[n-1]*w[n-1].

Is there some elegant expression (perhaps using lambda) to have it done
in one statement ? As in :
 y = lambda x,w : ...

I ask because the way I am doing it now :
  y = 0
  for i in range(0,n): y += x[i]*w[i]

doesn't seem very pythonic :)

Thanks,
Andrei

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Re: computing a weighted sum

[andreif]

Thanks Will, the 2.4 expression looks really nice.

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Re: computing a weighted sum

[andreif]

Even if language permits
  sum(x*w for x, w in zip(x, w))
would seem confusing for anyone watching the code

Maybe
   sum(xi*wi for xi, wi in zip(x, w)) 
would be more appropiate

Andrei

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