code: def df(self):
          
          data = self._final_data()
          
          if len(data) == 0:
              adf = pd.DataFrame(columns = [self.index.name, self.name])
              return adf.set_index(self.index.name)
              
          adf = pd.DataFrame(data)
          
          if len(adf.columns) != 2:
              msg = "Symbol ({}) needs to be cached prior to building a Dataframe"
              msg = msg.format(self.name)
              raise Exception(msg)
          adf.columns = [self.index.name, self.name]
          return self._finish_df(adf, 'FINAL')
docs: Note: this accessor is read-only.  It should be copied, if accessed in
          an application, more than once.
          
          Returns
          -------
              Dataframe of the symbol's final data.