How to load a video in a MovieClip node How to create a "CompositorNodeMovieClip" node and load a video using the python api in the node editor.

My progress so far...

bpy.context.scene.use_nodes = True 
nodes = bpy.data.scenes['Scene'].node_tree.nodes 
links = bpy.data.scenes['Scene'].node_tree.links # create the movieclip node 
movieClipNode = nodes.new("CompositorNodeMovieClip") # get the video clip 
videoClip = bpy.data.movieclips.get( videoPath ); 


but videoClip is returned as null..
you are using incorrect key , the key is the name of the movie clip 

#load new movie clip
bpy.data.movieclips.load(clip_path)
#get the new movie clip
movie_clip = bpy.data.movieclips.get(clip_name)
#assign movie clip to the node
bpy.context.scene.node_tree.nodes['Movie Clip'].clip = movie_clip