title: Joining Array In Python
body: <p>Hi I want to join multiple arrays in python, using numpy to form multidimensional arrays, it's inside of a for loop, this is a pseudocode</p>
  
  <pre><code>import numpy as np
  h = np.zeros(4)
  for x in range(3):
     x1 = some array of length of 4 returned from a previous function (3,5,6,7)
     h = np.concatenate((h,x1), axis =0)
  </code></pre>
  
  <p>The first iteration goes fine, but during the second iteration on the for loop I get the following error, </p>
  
  <blockquote>
    <p>ValueError: all the input arrays must have same number of dimensions</p>
  </blockquote>
  
  <p>The output array should look something like this</p>
  
  <pre><code> [[0,0,0,0],[3,5,6,7],[6,3,6,7]]
  </code></pre>
  
  <p>etc</p>
  
  <p>So how can I join the arrays? </p>
  
  <p>Thanks</p>