Toggle Manual Mode in Houdini

toggle_manual.py

def toggle_manual():
    """Toggle cook mode"""
    current_mode = hou.updateModeSetting()
    auto = (hou.updateMode.AutoUpdate, hou.updateMode.OnMouseUp)
    toggle_cook = hou.shelves.tool("toggle_manual")
    toggle_cook.setLabel("Auto Update")
    if current_mode in auto:
        hou.setUpdateMode(hou.updateMode.Manual)
        toggle_cook.setIcon("MISC_cook")
    elif current_mode == hou.updateMode.Manual:
        hou.setUpdateMode(hou.updateMode.AutoUpdate)
        toggle_cook.setIcon("BUTTONS_do_not")
        toggle_cook.setLabel("Manual Mode")
with hou.undos.disabler():
    toggle_manual()

Updated to exclude this from the undo stack (super annoying when trying to debug something heavy!), and added John Hughes' nifty icon switching logic

Make sure the tool is called toggle_manual wherever you've saved it.