title: Concat two arrays of different dimensions numpy
body: <p>I am trying to concatenate two numpy arrays to add an extra column: <code>array_1</code> is <code>(569, 30)</code> and <code>array_2</code> is is <code>(569, )</code></p>
  
  <p><code>combined = np.concatenate((array_1, array_2), axis=1)</code></p>
  
  <p>I thought this would work if I set <code>axis=2</code> so it will concatenate vertically. The end should should be a 569 x 31  array. </p>
  
  <p>The error I get is <code>ValueError: all the input arrays must have same number of dimensions</code></p>
  
  <p>Can someone help?</p>
  
  <p>Thx!</p>