title: How to make a new column of numpy arrays in a pandas data frame?
body: <p>I have the following data frame:</p>
  <pre class="lang-py prettyprint-override"><code>df = pd.DataFrame({'id': [1, 2, 3, 4],
                     'a': ['on', 'on', 'off', 'off'],
                     'b': ['on', 'off', 'on', 'off']})
  </code></pre>
  <p>How can I create a new column <code>df['new']</code> with the type of NumPy arrays/lists so that I can perform operations like:</p>
  <pre class="lang-py prettyprint-override"><code>df.loc[1, 'new'] = np.array([2 , 'l'])
  #or
  df.loc[1, 'new'] = [2 , 'l']
  </code></pre>