title: Is map(sum,zip(*list)) the fastest way to sum columns of list of arbitrary length?
body: <p>I would like to know if anyone can suggest a way to sum lists that is faster than map(sum, zip(*list)).</p>
  
  <p>Example:</p>
  
  <pre><code>import timeit
  
  print timeit.Timer('''
  [ (a[x]+b[x]+c[x]) for x in xrange(len(a)) ]
  ''', '''
  a = range(200)
  b = range(199,-1,-1)
  c = range(1,201)
  ''').timeit(number = 1000)
  
  print timeit.Timer('''
  map(sum,zip(*d))
  ''', '''
  a = range(200)
  b = range(199,-1,-1)
  c = range(1,201)
  d = [a,b,c]''').timeit(number = 1000)
  
  print timeit.Timer('''
  [sum(x) for x in zip(*d)]
  ''', '''
  a = range(200)
  b = range(199,-1,-1)
  c = range(1,201)
  d = [a,b,c]''').timeit(number = 1000)
  </code></pre>
  
  <p>Results:</p>
  
  <pre><code>0.0317891459248 #list comprehension
  0.0406545608382 #sum with zip
  0.0532605665307 #map sum with zip
  </code></pre>
  
  <p><strong>Note: I know I am nitpicking, but I'm just curious if anyone has a better suggestion.</strong></p>