title: Numpy: An efficient way to merge multiple slices
body: <p>I have a numpy array</p>
  
  <pre><code>test_array = np.arange(100).reshape((4,25))
  </code></pre>
  
  <p>and I want to merge the following cols to form a new array</p>
  
  <pre><code>1:3, 2:4, 3:15, 2:24, 6:8, 12:13
  </code></pre>
  
  <p>I know this code will work</p>
  
  <pre><code>np.hstack((test_array[:,1:3],test_array[:,2:4],test_array[:,3:15],test_array[:,2:24],test_array[:,6:8],test_array[:,12:13]))
  </code></pre>
  
  <p>But if there is any better way to avoid copying so many 'test_array', something like:</p>
  
  <pre><code>np.hstack((test_array[:,[1:3 2:4 3:15 2:24 6:8 12:13]]))
  </code></pre>