title: How to vectorize the sum of a string array in numpy?
body: <p>Is it possible to vectorize the calculation of the sum of a string array in numpy?</p>
  
  <p>With a loop, I would do this:</p>
  
  <pre><code>import numpy as np
  
  myarray = np.array(['a','b','c'])
  
  mysum = ''
  for i in myarray:
      mysum += i
  
  print(mysum) #result: 'abc'
  </code></pre>
  
  <p>For floats, one can simply use the sum function:</p>
  
  <pre><code>myarray_float = np.array([1.0,2.0,3.0])
  
  print(myarray_float.sum()) # result: 6.0
  </code></pre>
  
  <p>However, this is not possibe for arrays of strings, but leads to <em>Type error: cannot perform reduce with flexible type</em>.</p>