title: Retrieve delimiter infered by read_csv in pandas
body: <p>When using the configuration for automatic separator detection to read csv files (<code>pd.read_csv(file_path, sep=None)</code>), pandas tries to infer the delimiter (or separator). </p>
  
  <p>Is there a way to retrieve the result of this inference (the value that was finally used for <code>sep</code>)?</p>
  
  <p><strong>EDIT</strong></p>
  
  <p>I am looking specifically for a method that uses the pandas object that is returned by <code>read_csv</code>. I use version 0.20.2 of pandas.</p>