title: why I cannot suppress warning with regex using warnings.filterwarnings
body: <p>I want to suppress a specific type of warning using regular expression.
  The warning message is:</p>
  
  <pre><code>C:\Anaconda3\lib\site-packages\pandas\core\indexing.py:420: SettingWithCopyWarning:
  
  A value is trying to be set on a copy of a slice from a DataFrame.
  Try using .loc[row_indexer,col_indexer] = value instead
  
  See the caveats in the documentation: http://pandas.pydata.org/pandas-docs/stable/indexing.html#indexing-view-versus-copy 
  self.obj[item] = s
  </code></pre>
  
  <p>My way of suppressing filter:</p>
  
  <pre><code>import warnings
  warnings.filterwarnings("ignore", message= ".*A value is trying to.*")
  </code></pre>
  
  <p>However, it failed. I did try pasting  different part of the warning message into the regex but still failed. I want to know why. </p>