Where to find official learning resources about Python programming in RIR plug-ins

Excuse me, are there any official learning tutorials or materials about using Python in the RIR plug-in to interact in Revit, Rhino and Grasshopper?
At present, I can only see the webpage information of the Revit API defined by C# voice. Is there any content about the Revit API defined by Python?
For example: Where can the function be found directly?

Excuse me, where can I find the web resources of the Grasshopper API in RIR?
For example: Where can I find the function?
CG.AddGridLine(U, DB.XYZ(P.X, P.Y, P.Z), False)

If you search through YouTube, you can find some content about Revit API. @eirannejad has an awesome course called “Python for Revit”. Link to that here. I haven’t seen any resources specific to RIR python. But if you have Python knowledge, you can definitely start using by looking at already shared definitions on this forum as well as Dynamo forum.