czml3 documentation
From the official CZML Guide:
CZML is a JSON format for describing a time-dynamic graphical scene, primarily for display in a web browser running Cesium. It describes lines, points, billboards, models, and other graphical primitives, and specifies how they change with time.
czml3 aims to make the process of writing CZML files in Python easy by:
Type checking properties
Coercion of data to their required format
Forbidding unrecognised properties
Creating minimal CZML files
Performant JSON serialisation
User Manual: