In the object properties, you can **turn off the Ray Visibility** of the **Emission object** for the camera.

![enter image description here][1]

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You can also run this script to *enable or disable* the Camera Ray Visibility **for all objects** in the scene:

    import bpy
    
    for obj in bpy.data.objects:
        
        # toggle mesh lights
        if obj.type == 'MESH':
            nodes = obj.data.materials[0].node_tree.nodes
            for node in nodes:
                if node.type == "EMISSION":
                    obj.cycles_visibility.camera = not obj.cycles_visibility.camera
         
        # toggle lamps
        if obj.type == 'LAMP':
            obj.cycles_visibility.camera = not obj.cycles_visibility.camera



  [1]: https://i.sstatic.net/dXtKM.jpg