tt hscript

camera
if($F >= ch("start") && $F < ch("start") + ch("length"), 360 * ($F - ch("start")) / ch("length"), 0)

lights
if($F >= ch("start") && $F < ch("start") + ch("length"), -360 * ($F - ch("start")) / ch("length"), 0)


import hou

# Get HDA node
hda_node = hou.node("/obj/your_hda_node")

# Create nulls
null_camera = hda_node.createNode("null", "null_camera")
null_lights = hda_node.createNode("null", "null_lights")

# Set rotation expressions
null_camera.parm("ry").setExpression("if($F >= ch(\"start\") && $F < ch(\"start\") + ch(\"length\"), 360 * ($F - ch(\"start\")) / ch(\"length\"), 0)", hou.exprLanguage.Hscript)
null_lights.parm("ry").setExpression("if($F >= ch(\"start\") && $F < ch(\"start\") + ch(\"length\"), -360 * ($F - ch(\"start\")) / ch(\"length\"), 0)", hou.exprLanguage.Hscript)

# Add parameters to HDA
length_parm = hda_node.addParmTuple(hou.StringParmTemplate("length", "Length", 1, default_value=("240",), naming_scheme=hou.parmNamingScheme.Base1))
start_parm = hda_node.addParmTuple(hou.StringParmTemplate("start", "Start", 1, default_value=("1",), naming_scheme=hou.parmNamingScheme.Base1))

# Link parameters
null_camera.parm("length").set(length_parm[0])
null_camera.parm("start").set(start_parm[0])
null_lights.parm("length").set(length_parm[0])
null_lights.parm("start").set(start_parm[0])