Update CommandBase.py

- update to match CityOfZion#725 and also allow for subcommands to execute without arguments

Author: jseagrave21

neo/Prompt/CommandBase.py

@@ -66,18 +66,25 @@ def command_desc(self):
         pass
 
     # Raise KeyError exception if the command does not exist
-    def execute_sub_command(self, id, arguments):
-        self.__sub_commands[id].execute(arguments)
-
-    # ids: can be either a string or a list of strings.
-    def register_sub_command(self, ids, sub_command):
-        if isinstance(ids, list):
-            for id in ids:
-                self.__register_sub_command(id, sub_command)
+    def execute_sub_command(self, id, arguments=None):
+        if arguments is not None:
+            self.__sub_commands[id].execute(arguments)
         else:
-            self.__register_sub_command(ids, sub_command)
+            self.__sub_commands[id].execute()
 
-    def __register_sub_command(self, id, sub_command):
+    def register_sub_command(self, sub_command, additional_ids=[]):
+        """
+        Register a command as a subcommand.
+        It will have it's CommandDesc.command string used as id. Additional ids can be provided.
+         Args:
+            sub_command (CommandBase): Subcommand to register.
+            additional_ids (List[str]): List of additional ids. Can be empty.
+        """
+        self.__register_sub_command(sub_command, sub_command.command_desc().command)
+        for id in additional_ids:
+            self.__register_sub_command(sub_command, id)
+
+    def __register_sub_command(self, sub_command, id):
         if id in self.__sub_commands:
             raise ValueError(f"{id} is already a subcommand of {self.command_desc().command}.")
         if sub_command.__parent_command and sub_command.__parent_command != self: