Example of extending a menu in Unreal using Python

unreal_menu.py

"""

    Example of extending a menu in Unreal using Python

"""

import unreal

def main():

    menus = unreal.ToolMenus.get()

    # Find the 'edit' menu, this should not fail, 
    # but if we're looking for a menu we're unsure about 'if not' 
    # works as nullptr check,
    edit = menus.find_menu("LevelEditor.MainMenu.Edit")
    main_menu = menus.find_menu("LevelEditor.MainMenu")
    if not edit:
        print("Failed to find the 'Edit' menu")

    entry = unreal.ToolMenuEntry(
        name = "MyEntry",
        type = unreal.MultiBlockType.MENU_ENTRY, # If you pass a type that is not supported Unreal will let you know,
        insert_position = unreal.ToolMenuInsert("Delete", unreal.ToolMenuInsertType.AFTER) # this will tell unreal to insert this entry after the 'Delete' menu item, if found in section we define later,
    )

    entry.set_label("My Entry")
    entry.set_tool_tip("This is a Tool Menu Entry made in Python!")

    edit.add_menu_entry("EditMain", entry) # section name, ToolMenuInsert, Unreal will add the section name if it can't find it, otherwise call AddEntry for the found section,

    my_menu = main_menu.add_sub_menu("My.Menu", "Python", "My Menu", "This is a submenu")

    for name in ["Foo", "Bar", "Baz"]:
        e = unreal.ToolMenuEntry(
            name = name,
            type = unreal.MultiBlockType.MENU_ENTRY, # If you pass a type that is not supported Unreal will let you know,
        )
        e.set_label(name)
        my_menu.add_menu_entry("Items", e)

    menus.refresh_all_widgets()

if __name__ == '__main__':
    main()

Thanks worked out of the box for 5.4.4