title: Correct way to select a specific column from the last row of a Dataframe
body: <p>I have a dataframe <code>stock_pick</code> and trying to set last row of certain column like</p>
  
  <pre><code>stock_pick.iloc[-1]["Regime"] = 0
  </code></pre>
  
  <p>This results in the ,</p>
  
  <pre><code>/home/prowler/analysis-toolkit/anaconda2/envs/py3.6/lib/python3.6/site-packages/pandas/core/indexing.py:179: SettingWithCopyWarning: 
  A value is trying to be set on a copy of a slice from a DataFrame
  
  See the caveats in the documentation: http://pandas.pydata.org/pandas-docs/stable/indexing.html#indexing-view-versus-copy
    self._setitem_with_indexer(indexer, value)
  </code></pre>
  
  <p>What is the correct way to pick and assign a value to a specific column in the last row?</p>