record with the fields: 'locale: record with the fields: 'symbol: list with values of type: string (optional)', 'decimal: string (optional)', 'group: string (optional)', 'grouping: list with values of type: number (optional)', 'numerals: list with values of type: string (optional)', 'percent: string (optional)', 'separate_4digits: boolean (optional)' (optional)', 'nully: boolean | number | string | record | list (optional)', 'prefix: number (optional)', 'specifier: string (optional)' The formatting applied to the column's data. This prop is derived from the [d3-format](https://github.com/d3/d3-format) library specification. Apart from being structured slightly differently (under a single prop), the usage is the same. See also dash_table.FormatTemplate. It contains helper functions for typical number formats.