Changed do_help() so that argparsers print their own help.

Author: kmvanbrunt

cmd2/argparse_completer.py

@@ -10,6 +10,7 @@
     deque,
 )
 from typing import (
+    IO,
     TYPE_CHECKING,
     Optional,
     Union,
@@ -624,24 +625,28 @@ def complete_subcommand_help(self, text: str, line: str, begidx: int, endidx: in
                 break
         return []
 
-    def format_help(self, tokens: list[str]) -> str:
-        """Supports cmd2's help command in the retrieval of help text.
+    def print_help(self, tokens: list[str], file: Optional[IO[str]] = None) -> None:
+        """Supports cmd2's help command in the printing of help text.
 
         :param tokens: arguments passed to help command
-        :return: help text of the command being queried.
+        :param file: optional file object where the argparse should write help text
+                     If not supplied, argparse will write to sys.stdout.
         """
-        # If our parser has subcommands, we must examine the tokens and check if they are subcommands
+        # If our parser has subcommands, we must examine the tokens and check if they are subcommands.
         # If so, we will let the subcommand's parser handle the rest of the tokens via another ArgparseCompleter.
-        if self._subcommand_action is not None:
-            for token_index, token in enumerate(tokens):
-                if token in self._subcommand_action.choices:
-                    parser: argparse.ArgumentParser = self._subcommand_action.choices[token]
-                    completer_type = self._cmd2_app._determine_ap_completer_type(parser)
+        if tokens and self._subcommand_action is not None:
+            parser = cast(
+                Optional[argparse.ArgumentParser],
+                self._subcommand_action.choices.get(tokens[0]),
+            )
 
-                    completer = completer_type(parser, self._cmd2_app)
-                    return completer.format_help(tokens[token_index + 1 :])
-                break
-        return self._parser.format_help()
+            if parser:
+                completer_type = self._cmd2_app._determine_ap_completer_type(parser)
+                completer = completer_type(parser, self._cmd2_app)
+                completer.print_help(tokens[1:])
+                return
+
+        self._parser.print_help(file=file)
 
     def _complete_arg(
         self,

cmd2/cmd2.py

@@ -3876,9 +3876,7 @@ def do_help(self, args: argparse.Namespace) -> None:
             # If the command function uses argparse, then use argparse's help
             if func is not None and argparser is not None:
                 completer = argparse_completer.DEFAULT_AP_COMPLETER(argparser, self)
-
-                # Set end to blank so the help output matches how it looks when "command -h" is used
-                self.poutput(completer.format_help(args.subcommands), end='')
+                completer.print_help(args.subcommands, self.stdout)
 
             # If there is a help func delegate to do_help
             elif help_func is not None: