Fixed handling of argparse's default optionals group name that was changed in Python 3.10

Author: kmvanbrunt

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.1.1 (TBD, 2021)
+* Bug Fixes
+   * Fixed handling of argparse's default optionals group name that was changed in Python 3.10
+
 ## 2.1.0 (June 14, 2021)
 * Enhancements
    * Converted persistent history files from pickle to compressed JSON

cmd2/argparse_custom.py

@@ -973,9 +973,14 @@ def format_help(self) -> str:
 
         # Begin cmd2 customization (separate required and optional arguments)
 
+        if sys.version_info >= (3, 10):
+            default_optionals_title = 'options'
+        else:
+            default_optionals_title = 'optional arguments'
+
         # positionals, optionals and user-defined groups
         for action_group in self._action_groups:
-            if action_group.title == 'optional arguments':
+            if action_group.title == default_optionals_title:
                 # check if the arguments are required, group accordingly
                 req_args = []
                 opt_args = []
@@ -992,7 +997,7 @@ def format_help(self) -> str:
                 formatter.end_section()
 
                 # now display truly optional arguments
-                formatter.start_section(action_group.title)
+                formatter.start_section('optional arguments')
                 formatter.add_text(action_group.description)
                 formatter.add_arguments(opt_args)
                 formatter.end_section()

cmd2/utils.py

@@ -131,8 +131,9 @@ def __init__(
                          validation using str_to_bool(). The val_type function should raise an exception if it fails.
                          This exception will be caught and printed by Cmd.do_set().
         :param description: string describing this setting
-        :param settable_object: Object to configure with the set command
-        :param settable_attrib_name: Attribute name to be modified. Defaults to `name` if not specified.
+        :param settable_object: object to which the instance attribute belongs (e.g. self)
+        :param settable_attrib_name: name which displays to the user in the output of the set command.
+                                     Defaults to `name` if not specified.
         :param onchange_cb: optional function or method to call when the value of this settable is altered
                             by the set command. (e.g. onchange_cb=self.debug_changed)