Placing plugin or action in submenu using PyQGIS or PyQT

Question

I am trying to place a plugin into a submenu of "Vector". In this case "Geoprocessing Tools".

When I use:

iface.addPluginToVectorMenu('Geoprocessing Tools',action) 

or:

iface.addPluginToVectorMenu('&Geoprocessing Tools',action) 

it creates a new and double submenu "Geoprocessing Tools" with the action placed only in the new one. Do I miss some formatting rules or is it just not possible?

Answer 1

It can be improved (tests, search of the submenu text) but the code below will add your action in the right Geoprocessing Tools submenu :

def add_plugin_to_geoprocessing_menu(action: QAction) -> bool:
    vector_menu = iface.vectorMenu()
    geoprocessing_action = [
        a for a in vector_menu.findChildren(QAction) if "Geoprocessing" in a.text()
    ][0]
    geoprocessing_menu = geoprocessing_action.menu()
    geoprocessing_menu.addAction(action)
    return True


add_plugin_to_geoprocessing_menu(action)