Fixed RecursionError when printing an argparse.Namespace caused by custom attribute cmd2 was adding

Added get_statement() function to argparse.Namespace which returns __statement__ attribute

3 files changed, 15 insertions, 14 deletions

diff --git a/cmd2/cmd2.py b/cmd2/cmd2.py
index da576805..bc6691f6 100644
--- a/cmd2/cmd2.py
+++ b/cmd2/cmd2.py
@@ -663,7 +663,9 @@ class Cmd(cmd.Cmd):
                 raise CommandSetRegistrationError('Could not find argparser for command "{}" needed by subcommand: {}'
                                                   .format(command_name, str(method)))
 
-            subcmd_parser.set_defaults(cmd2_handler=method)
+            # Set the subcommand handler function
+            defaults = {constants.NS_ATTR_SUBCMD_HANDLER: method}
+            subcmd_parser.set_defaults(**defaults)
 
             def find_subcommand(action: argparse.ArgumentParser, subcmd_names: List[str]) -> argparse.ArgumentParser:
                 if not subcmd_names:
diff --git a/cmd2/constants.py b/cmd2/constants.py
index 9eaa9957..037a7cab 100644
--- a/cmd2/constants.py
+++ b/cmd2/constants.py
@@ -37,10 +37,6 @@ HELP_FUNC_PREFIX = 'help_'
 # All command completer functions start with this
 COMPLETER_FUNC_PREFIX = 'complete_'
 
-##############################################################################
-# The following are optional attributes added to do_* command functions
-##############################################################################
-
 # The custom help category a command belongs to
 CMD_ATTR_HELP_CATEGORY = 'help_category'
 
@@ -50,9 +46,6 @@ CMD_ATTR_ARGPARSER = 'argparser'
 # Whether or not tokens are unquoted before sending to argparse
 CMD_ATTR_PRESERVE_QUOTES = 'preserve_quotes'
 
-# optional attribute
-SUBCMD_HANDLER = 'cmd2_handler'
-
 # subcommand attributes for the base command name and the subcommand name
 SUBCMD_ATTR_COMMAND = 'parent_command'
 SUBCMD_ATTR_NAME = 'subcommand_name'
@@ -60,3 +53,7 @@ SUBCMD_ATTR_ADD_PARSER_KWARGS = 'subcommand_add_parser_kwargs'
 
 # arpparse attribute linking to command set instance
 PARSER_ATTR_COMMANDSET = 'command_set'
+
+# custom attributes added to argparse Namespaces
+NS_ATTR_SUBCMD_HANDLER = '__subcmd_handler__'
+NS_ATTR_STATEMENT = '__statement__'
diff --git a/cmd2/decorators.py b/cmd2/decorators.py
index 689f29c5..ccbbd832 100644
--- a/cmd2/decorators.py
+++ b/cmd2/decorators.py
@@ -1,7 +1,6 @@
 # coding=utf-8
 """Decorators for ``cmd2`` commands"""
 import argparse
-import types
 from typing import TYPE_CHECKING, Any, Callable, Dict, Iterable, List, Optional, Tuple, Union
 
 from . import constants
@@ -190,6 +189,7 @@ def with_argparser_and_unknown_args(parser: argparse.ArgumentParser, *,
              of unknown argument strings. A member called ``__statement__`` is added to the
              ``Namespace`` to provide command functions access to the :class:`cmd2.Statement`
              object. This can be useful if the command function needs to know the command line.
+             ``__statement__`` can also be retrieved by calling ``get_statement()`` on the ``Namespace``.
 
     :Example:
 
@@ -228,6 +228,7 @@ def with_argparser(parser: argparse.ArgumentParser, *,
     :return: function that gets passed the argparse-parsed args in a Namespace
              A member called __statement__ is added to the Namespace to provide command functions access to the
              Statement object. This can be useful if the command function needs to know the command line.
+             ``__statement__`` can also be retrieved by calling ``get_statement()`` on the ``Namespace``.
 
     :Example:
 
@@ -297,12 +298,13 @@ def with_argparser(parser: argparse.ArgumentParser, *,
             except SystemExit:
                 raise Cmd2ArgparseError
             else:
-                setattr(ns, '__statement__', statement)
+                # Add statement to Namespace and a getter function for it
+                setattr(ns, constants.NS_ATTR_STATEMENT, statement)
+                setattr(ns, 'get_statement', lambda: statement)
 
-                def get_handler(ns_self: argparse.Namespace) -> Optional[Callable]:
-                    return getattr(ns_self, constants.SUBCMD_HANDLER, None)
-
-                setattr(ns, 'get_handler', types.MethodType(get_handler, ns))
+                # Add getter function for subcmd handler, which can be None
+                subcmd_handler = getattr(ns, constants.NS_ATTR_SUBCMD_HANDLER, None)
+                setattr(ns, 'get_handler', lambda: subcmd_handler)
 
                 args_list = _arg_swap(args, statement, *new_args)
                 return func(*args_list, **kwargs)