Update argparse.py from CPython v3.12.0

Author: NakanoMiku39

Lib/argparse.py

@@ -345,21 +345,22 @@ def _format_usage(self, usage, actions, groups, prefix):
                 def get_lines(parts, indent, prefix=None):
                     lines = []
                     line = []
+                    indent_length = len(indent)
                     if prefix is not None:
                         line_len = len(prefix) - 1
                     else:
-                        line_len = len(indent) - 1
+                        line_len = indent_length - 1
                     for part in parts:
                         if line_len + 1 + len(part) > text_width and line:
                             lines.append(indent + ' '.join(line))
                             line = []
-                            line_len = len(indent) - 1
+                            line_len = indent_length - 1
                         line.append(part)
                         line_len += len(part) + 1
                     if line:
                         lines.append(indent + ' '.join(line))
                     if prefix is not None:
-                        lines[0] = lines[0][len(indent):]
+                        lines[0] = lines[0][indent_length:]
                     return lines
 
                 # if prog is short, follow it with optionals or positionals
@@ -403,10 +404,18 @@ def _format_actions_usage(self, actions, groups):
             except ValueError:
                 continue
             else:
-                end = start + len(group._group_actions)
+                group_action_count = len(group._group_actions)
+                end = start + group_action_count
                 if actions[start:end] == group._group_actions:
+
+                    suppressed_actions_count = 0
                     for action in group._group_actions:
                         group_actions.add(action)
+                        if action.help is SUPPRESS:
+                            suppressed_actions_count += 1
+
+                    exposed_actions_count = group_action_count - suppressed_actions_count
+
                     if not group.required:
                         if start in inserts:
                             inserts[start] += ' ['
@@ -416,7 +425,7 @@ def _format_actions_usage(self, actions, groups):
                             inserts[end] += ']'
                         else:
                             inserts[end] = ']'
-                    else:
+                    elif exposed_actions_count > 1:
                         if start in inserts:
                             inserts[start] += ' ('
                         else:
@@ -490,7 +499,6 @@ def _format_actions_usage(self, actions, groups):
         text = _re.sub(r'(%s) ' % open, r'\1', text)
         text = _re.sub(r' (%s)' % close, r'\1', text)
         text = _re.sub(r'%s *%s' % (open, close), r'', text)
-        text = _re.sub(r'\(([^|]*)\)', r'\1', text)
         text = text.strip()
 
         # return the text
@@ -875,16 +883,19 @@ def __call__(self, parser, namespace, values, option_string=None):
         raise NotImplementedError(_('.__call__() not defined'))
 
 
+# FIXME: remove together with `BooleanOptionalAction` deprecated arguments.
+_deprecated_default = object()
+
 class BooleanOptionalAction(Action):
     def __init__(self,
                  option_strings,
                  dest,
                  default=None,
-                 type=None,
-                 choices=None,
+                 type=_deprecated_default,
+                 choices=_deprecated_default,
                  required=False,
                  help=None,
-                 metavar=None):
+                 metavar=_deprecated_default):
 
         _option_strings = []
         for option_string in option_strings:
@@ -894,6 +905,24 @@ def __init__(self,
                 option_string = '--no-' + option_string[2:]
                 _option_strings.append(option_string)
 
+        # We need `_deprecated` special value to ban explicit arguments that
+        # match default value. Like:
+        #   parser.add_argument('-f', action=BooleanOptionalAction, type=int)
+        for field_name in ('type', 'choices', 'metavar'):
+            if locals()[field_name] is not _deprecated_default:
+                warnings._deprecated(
+                    field_name,
+                    "{name!r} is deprecated as of Python 3.12 and will be "
+                    "removed in Python {remove}.",
+                    remove=(3, 14))
+
+        if type is _deprecated_default:
+            type = None
+        if choices is _deprecated_default:
+            choices = None
+        if metavar is _deprecated_default:
+            metavar = None
+
         super().__init__(
             option_strings=_option_strings,
             dest=dest,
@@ -2165,7 +2194,9 @@ def _read_args_from_files(self, arg_strings):
             # replace arguments referencing files with the file content
             else:
                 try:
-                    with open(arg_string[1:]) as args_file:
+                    with open(arg_string[1:],
+                              encoding=_sys.getfilesystemencoding(),
+                              errors=_sys.getfilesystemencodeerrors()) as args_file:
                         arg_strings = []
                         for arg_line in args_file.read().splitlines():
                             for arg in self.convert_arg_line_to_args(arg_line):
@@ -2479,9 +2510,11 @@ def _get_values(self, action, arg_strings):
               not action.option_strings):
             if action.default is not None:
                 value = action.default
+                self._check_value(action, value)
             else:
+                # since arg_strings is always [] at this point
+                # there is no need to use self._check_value(action, value)
                 value = arg_strings
-            self._check_value(action, value)
 
         # single argument or optional argument produces a single value
         elif len(arg_strings) == 1 and action.nargs in [None, OPTIONAL]:
@@ -2523,7 +2556,6 @@ def _get_value(self, action, arg_string):
 
         # ArgumentTypeErrors indicate errors
         except ArgumentTypeError as err:
-            name = getattr(action.type, '__name__', repr(action.type))
             msg = str(err)
             raise ArgumentError(action, msg)
 
@@ -2595,9 +2627,11 @@ def print_help(self, file=None):
 
     def _print_message(self, message, file=None):
         if message:
-            if file is None:
-                file = _sys.stderr
-            file.write(message)
+            file = file or _sys.stderr
+            try:
+                file.write(message)
+            except (AttributeError, OSError):
+                pass
 
     # ===============
     # Exiting methods