code: def write_csvs(self,
                     asset_map,
                     show_progress=False,
                     invalid_data_behavior='warn'):
          
          read = partial(
              read_csv,
              parse_dates=['day'],
              index_col='day',
              dtype=self._csv_dtypes,
          )
          return self.write(
              ((asset, read(path)) for asset, path in iteritems(asset_map)),
              assets=viewkeys(asset_map),
              show_progress=show_progress,
              invalid_data_behavior=invalid_data_behavior,
          )
docs: Read CSVs as DataFrames from our asset map.
  
          Parameters
          ----------
          asset_map : dict[int -> str]
              A mapping from asset id to file path with the CSV data for that
              asset
          show_progress : bool
              Whether or not to show a progress bar while writing.
          invalid_data_behavior : {'warn', 'raise', 'ignore'}
              What to do when data is encountered that is outside the range of
              a uint32.