title: How to insert numpy 1D array to numpy 3D array?
body: <p>So I've got a 3-dimensional numpy array and I want to insert into it a 1-dimensional numpy array. How can I do it?
  <br>For example, this is my 3D array and I want to insert [2,2,2] </p>
  
  <pre class="lang-py prettyprint-override"><code>[[[1,1,1],
    [3,3,3],
    [4,4,4]],
   [[5,5,5],
    [6,6,6],
    [7,7,7]]]
  </code></pre>
  
  <p>so it looks like this:</p>
  
  <pre><code>[[[1,1,1],
    [2,2,2],
    [3,3,3],
    [4,4,4]],
   [[5,5,5],
    [6,6,6],
    [7,7,7]]]
  </code></pre>
  
  <p>How can I do it?</p>