Streamline ending point


I am learning to use the stream tracer filter. I have already created a customized source for the seeding points, and it successfully gives the field lines. However, the next step is to pick points from the customized source based on the connectivity, i.e. whether the field lines end on the boundaries and on which boundary. How should I achieve this goal?

My current understand is that each seed point has a unique SeedIds, and the streamlines passing through the seed points are saved as Polygonal Mesh. If from the python interface I can get the coordinates from each streamline, then I can assign a new variable based on the location of the streamline end points, and do further analysis later on. It would be really helpful if there is a document about the python module on how to obtain data info from Paraview.