title: How to use `numpy.savez` in a loop for save more than one array?
body: <p>From a loop I'm getting an array. I want to save this arrays in a <code>tempfile</code>.
  The problem is that <code>np.savez</code> only saves the last array from the loop. I think I understand why this happens, but dont know how to do it better.</p>
  
  <p>To solve my problem I had the idea to open the tempfile in <code>mode=a+b</code> with the goal to append the new arrays from the loop. But this doesn't work.</p>
  
  <p>My code so far:</p>
  
  <pre><code>tmp = TemporaryFile(mode="a+b")    
  for i in range(10):
    array = getarray[i]  #demo purpose
    np.savez(tmp,array)
  tmp.seek(0)
  </code></pre>
  
  <p>Then using the tempfile to read the arrays:</p>
  
  <pre><code>tmp_read = np.load(tmp)
  print tmp_read.files
  [OUTPUT]: ['arr_0']
  </code></pre>
  
  <p>But I want 10 arrays in the tempfile. Any ideas?<br>
  thanks</p>