title: Python Numpy appending multiple lists from objects
body: <p>I am calling an object several times that is returning a numpy list:</p>
  
  <pre><code>for x in range(0,100):
          d = simulation3()
  
  d = [0, 1, 2, 3]
  d = [4, 5, 6, 7]
  </code></pre>
  
  <p>..and many more</p>
  
  <p>I want to take each list and append it to a 2D array.</p>
  
  <p><code>final_array = [[0, 1, 2, 3],[4, 5, 6, 7]</code>...and so forth]</p>
  
  <p>I tried creating an empty array (<code>final_array = np.zeros(4,4)</code>) and appending it but the values are appending after the <code>4X4 matrix</code> is created.  </p>
  
  <p>Can anyone help me with this?  thank you!</p>