title: Convert columns from a data frame to a list of dicts efficiently
body: <p>I am converting columns of data frame to to a list of dictionaries, however, due to the number of columns and number of observations in my data frame I run out of memory using my current approach:</p>
  
  <pre><code>df = pd.DataFrame(np.random.randn(10, 3), columns=['a', 'b', 'c'])
  df.T.to_dict().values()
  </code></pre>
  
  <p>Is there a more efficient way I can do this?</p>