title: Cope with different slicing-behaviour in scipy.sparse and numpy
body: <p><strong><em>Setup</em></strong></p>
  
  <p>I'm aware of the fact that sparse matrices in scipy's <code>.sparse</code>-module differ from <code>numpy</code>-arrays. Also, I'm aware of questions like <a href="https://stackoverflow.com/questions/13843352/what-is-the-fastest-way-to-slice-a-scipy-sparse-matrix">here</a> regarding slicing of sparse arrays. Anyhow, this and most other questions deal with the performance of slicing.</p>
  
  <p>My question rather deals with how to cope with their different slicing-behaviour. Lets create an example:</p>
  
  <pre class="lang-py prettyprint-override"><code>import numpy as np
  from scipy import sparse
  
  matrix = np.asarray([[0,0,0,1], [1,1,0,0], [1,0,1,0], [1,0,0,1], [1,0,0,1], [1,0,0,1]])
  sparse_matrix = sparse.lil_matrix(matrix) # Or another format like .csr_matrix etc.
  </code></pre>
  
  <p>Given this setup, applying the same slice results in a different output:</p>
  
  <pre class="lang-py prettyprint-override"><code>matrix[:, 3]
  # Output: 
  # array([ True, False, False,  True,  True,  True], dtype=bool)
  
  sparse_matrix[:, 3]
  # Output:
  # matrix([[ True],
  #        [False],
  #        [False],
  #        [ True],
  #        [ True],
  #        [ True]], dtype=bool)
  </code></pre>
  
  <p><strong><em>Question</em></strong></p>
  
  <p>This is a bit of a bummer, since I need the first output to apply in the second case as well. As said in the beginning, I know that using <code>sparse_matrix.A</code> etc. will give me the desired result. Anyhow, converting the sparse matrix to an array contradicts with the initial use-case of sparse-matrices.</p>
  
  <p>So is there some possibility to achieve the same slice-result without converting <code>sparse-matrix</code> to an array?</p>
  
  <p><strong>Edit:</strong>
  For clarification, since my question might be confusing regarding this: The slice on the <code>sparse_matrix</code> shall have the same output as <code>matrix</code>, meaning that something like <code>sparse_matrix[:, 3]</code> shall output <code>([ True, False, False,  True,  True,  True])</code>.</p>