Fusion Comp Script, renames all loader and saver nodes inside the active comp with the filename, without extension, of their Clip.

fusion_renamenodesfromclip.py

# stdlib module
import os


if __name__ == "__main__":
    # get all loaders in current comp
    loaders = comp.GetToolList(False, "Loader").values()
    savers = comp.GetToolList(False, "Saver").values()
    
    nodes = []
    nodes.extend(loaders)
    nodes.extend(savers)
    
    for node in nodes:
        old_name = node.Name
        
        # get clip from node
        clip = node.Clip[0]
        
        # skip nodes with an empty clip
        if not clip:
            continue

        # build new node name from clip
        filename = os.path.basename(node.Clip[0])
        new_name = os.path.splitext(filename)[0]
        
        # only update node name when current name is different from new name
        if old_name != new_name:
            node.SetAttrs({"TOOLS_Name": new_name, "TOOLB_NameSet": 1})
            print("renamed {} {!r} to {!r}".format(node.ID, old_name, new_name))