Version 4.2.0

• Update Vega-Lite from version 4.8.1 to version 4.17.0; see Vega-Lite Release Notes.

Enhancements

• Pie charts are now supported through the use of mark_arc. (Examples: eg. Pie Chart and Radial Chart)
• Support for the datum encoding specifications from Vega-Lite; see Vega-Lite Datum Definition. (Examples: Line Chart with datum and Line Chart with datum for color.)
• angle encoding can now be used to control point styles (Example: Wind Vector Map)
• Support for serialising pandas nullable data types for float data (#2399).
• Automatically create an empty data object when Chart is called without a data parameter (#2515).
• Allow the use of pathlib Paths when saving charts (#2355).
• Support deepcopy for charts (#2403).

Bug Fixes

• Fix to_dict() for nested selections (#2120).
• Fix item access for expressions (#2099).