problems with node editor commands for an append group

Hello! Please excuse my bad english … I’ve got a problem with my python script…

First I create a circle, make some changes to the location and so one and give them some materials in the node editor.

Then I append a group, make some changes to the location and try to give them some materials in the node editor too.
BUT heres my problem … every change in the node editor is given to the circle and not to the group … I can change the location of the group but after that its like the group is not the active object and so my circle get all the commands for the node editor … here you can see the part of my script:

First part … the circle:

bpy.ops.mesh.primitive_circle_add(vertices = a, fill_type = 'NGON')
    
    i = 0
    while (i < a):
        y = -1*( listx[i+1])
        x = listy[i+1]
        
        context=bpy.context
    
    
        for obj in context.selected_objects:
            obj.location = (0,0,0)
        
            if obj.type=='MESH':
                for v in obj.data.vertices[i:(i+1)]:
                    v.co = x,y,z
    
        i = i +1
    
    for obj in context.selected_objects:
    
        #bpy.ops.object.mode_set(mode='EDIT')
        #bpy.ops.uv.smart_project()
        #bpy.ops.object.mode_set(mode='OBJECT')
        obj.data.materials.append(materialfloor)
        obj.rotation_euler[0]=RotationUmX*0.0174533
        obj.rotation_euler[2]=RotationUmZ*0.0174533
        obj.location=(PositionX,PositionY,PositionZ)
        
        
        bpy.ops.object.mode_set(mode='EDIT')
        bpy.ops.uv.unwrap(method='ANGLE_BASED', margin=0.001)
        
        
        bpy.context.area.type = 'NODE_EDITOR'
        bpy.context.object.active_material.use_nodes = True
        
        
        bpy.context.scene.use_nodes = True
        tree = bpy.context.object.active_material.node_tree
        links = tree.links
        
        for n in tree.nodes:
            tree.nodes.remove(n)
        ...

second part … the group:

bpy.ops.wm.link_append(link = False, instance_groups = False, filepath="...", filename="...", directory="...")
    
    
    
    
    
    context = bpy.context
    for obj in context.selected_objects:
        obj.location = (x,y,z)
        obj.rotation_euler[0] = RotX*0.0174533
        obj.rotation_euler[1] = RotY*0.0174533
        obj.rotation_euler[2] = RotZ*0.0174533
        
        
        bpy.ops.object.transform_apply(location=False, rotation=False, scale=True)
        
        
        bpy.ops.object.mode_set(mode='EDIT')
        bpy.ops.uv.unwrap(method='ANGLE_BASED', margin=0.001)
        
        
        bpy.context.area.type = 'NODE_EDITOR'
        bpy.context.object.active_material.use_nodes = True
        
        
        bpy.context.scene.use_nodes = True
        tree = bpy.context.object.active_material.node_tree
        links = tree.links
        
        for n in tree.nodes:
            tree.nodes.remove(n)
             ...

Hope anybody can help me … Thanks a lot!

please wrap your code with code tags

[CODE ]like this, just without the space before the closing brackets[/CODE ]