'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.'

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)
