code: def get_dataframe(self):
          
          assert self.dataframe is not None, (
              "'%s' should either include a `dataframe` attribute, "
              "or override the `get_dataframe()` method."
              % self.__class__.__name__
          )
  
          dataframe = self.dataframe
          return dataframe
docs: Get the DataFrame for this view.
          Defaults to using `self.dataframe`.
  
          This method should always be used rather than accessing `self.dataframe`
          directly, as `self.dataframe` gets evaluated only once, and those results
          are cached for all subsequent requests.
  
          You may want to override this if you need to provide different
          dataframes depending on the incoming request.