How to write python code to read pointcloud data from a bag file and display using RVIZ api ?. Can any one help me where to find RVIZ python APIs ? to read bag file and display

I've a bag file. I need to write a Python Application which reads that bag file and display on RVIZ. but i'm not finding any RVIZ APIs tutorial to use. Could you please help me how to proceed in this task ? Thanks