title: How to transform a 3d arrays into a dataframe in python
body: <p>I have a 3d array as follows:</p>
  <pre class="lang-py prettyprint-override"><code>    ThreeD_Arrays = np.random.randint(0, 1000, (5, 4, 3))
      
      array([[[715, 226, 632],
              [305,  97, 534],
              [ 88, 592, 902],
              [172, 932, 263]],
  
             [[895, 837, 431],
              [649, 717,  39],
              [363, 121, 274],
              [334, 359, 816]],
  
             [[520, 692, 230],
              [452, 816, 887],
              [688, 509, 770],
              [290, 856, 584]],
  
             [[286, 358, 462],
              [831,  26, 332],
              [424, 178, 642],
              [955,  42, 938]], 
  
             [[ 44, 119, 757],
              [908, 937, 728],
              [809,  28, 442],
              [832, 220, 348]]])
  </code></pre>
  <p>Now I would like to have it into a <code>DataFrame</code> like this:</p>
  <p><a href="https://i.stack.imgur.com/5UvY0.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/5UvY0.png" alt="the expected results is shown here" /></a></p>
  <p>Add a <code>Date</code> column like indicated and the column names <code>A</code>, <code>B</code>, <code>C</code>.</p>
  <p>How to do this transformation? Thanks!</p>