title: Add numpy array as column to Pandas data frame
body: <p>I have a Pandas data frame object of shape (X,Y) that looks like this:</p>
  
  <pre><code>[[1, 2, 3],
  [4, 5, 6],
  [7, 8, 9]]
  </code></pre>
  
  <p>and a numpy sparse matrix (CSC) of shape (X,Z) that looks something like this</p>
  
  <pre><code>[[0, 1, 0],
  [0, 0, 1],
  [1, 0, 0]]
  </code></pre>
  
  <p>How can I add the content from the matrix to the data frame in a new named column such that the data frame will end up like this:</p>
  
  <pre><code>[[1, 2, 3, [0, 1, 0]],
  [4, 5, 6, [0, 0, 1]],
  [7, 8, 9, [1, 0, 0]]]
  </code></pre>
  
  <p>Notice the data frame now has shape (X, Y+1) and rows from the matrix are elements in the data frame.</p>