title: Addition of multiple arrays in python
body: <p>I have a number of arrays that I wish to broadcast into a single array using addition, which I know can be simply done such that:</p>
  
  <pre><code>a = numpy.array([1,2,3])
  b = numpy.array9[4,5,6])
  sum = a + b
  print(sum)
  
  [5,7,9]
  </code></pre>
  
  <p>However, I can't hardcode it like in this simple example as I will run my script numerous times with a different number of inputs and so will have a different number of arrays each time. Sometimes, I may have a and b, but other times I may have a, c and d but not b etc.</p>
  
  <p>Using a loop I therefore append the arrays I do have into a list, so that I end up with something like:</p>
  
  <pre><code>newlist = [array([1,2,3,...5,4,3]), 
            array([5,7,2,...4,6,7]),
            array([3,6,2,...4,5,9])]
  </code></pre>
  
  <p>What would be the most pythonic way of getting a single array from the arrays in 'newlist' which is the addition of the arrays within it, such that (from newlist):</p>
  
  <pre><code>sum = [8,15,7,...14,15,19]
  </code></pre>
  
  <p>The arrays are all the same shape.</p>