Merge branch 'pre-commit-ci-update-config'

updates:
- [github.com/asottile/pyupgrade: v3.15.0 → v3.15.1](https://github.com/asottile/pyupgrade/compare/v3.15.0...v3.15.1)

.pre-commit-config.yaml

@@ -1,6 +1,6 @@
 repos:
 -   repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v4.4.0
+    rev: v4.5.0
     hooks:
     -   id: trailing-whitespace
     -   id: end-of-file-fixer
@@ -10,38 +10,38 @@ repos:
     -   id: name-tests-test
     -   id: requirements-txt-fixer
 -   repo: https://github.com/asottile/setup-cfg-fmt
-    rev: v2.3.0
+    rev: v2.5.0
     hooks:
     -   id: setup-cfg-fmt
 -   repo: https://github.com/asottile/reorder-python-imports
-    rev: v3.9.0
+    rev: v3.12.0
     hooks:
     -   id: reorder-python-imports
         args: [--py38-plus, --add-import, 'from __future__ import annotations']
 -   repo: https://github.com/asottile/add-trailing-comma
-    rev: v2.4.0
+    rev: v3.1.0
     hooks:
     -   id: add-trailing-comma
         args: [--py36-plus]
 -   repo: https://github.com/asottile/dead
-    rev: v1.5.1
+    rev: v1.5.2
     hooks:
     -   id: dead
 -   repo: https://github.com/asottile/pyupgrade
-    rev: v3.4.0
+    rev: v3.15.1
     hooks:
     -   id: pyupgrade
         args: [--py38-plus]
--   repo: https://github.com/pre-commit/mirrors-autopep8
-    rev: v2.0.2
+-   repo: https://github.com/hhatto/autopep8
+    rev: v2.0.4
     hooks:
     -   id: autopep8
 -   repo: https://github.com/PyCQA/flake8
-    rev: 6.0.0
+    rev: 7.0.0
     hooks:
     -   id: flake8
         additional_dependencies: [flake8-encodings, flake8-warnings, flake8-builtins, flake8-length, flake8-print]
 -   repo: https://github.com/pre-commit/mirrors-mypy
-    rev: v1.3.0
+    rev: v1.8.0
     hooks:
     -   id: mypy

README.md

@@ -29,14 +29,14 @@ $ python -m settngs
 Hello lordwelch
 $ python -m settngs -v
 Hello lordwelch
-merged_namespace.values.example_verbose=True
+merged_namespace.values.Example_Group__verbose=True
 $ python -m settngs -v -s
 Hello lordwelch
 Successfully saved settings to settings.json
-merged_namespace.values.example_verbose=True
+merged_namespace.values.Example_Group__verbose=True
 $ python -m settngs
 Hello lordwelch
-merged_namespace.values.example_verbose=True
+merged_namespace.values.Example_Group__verbose=True
 $ cat >settings.json << EOF
 {
   "example": {
@@ -64,7 +64,7 @@ Hello world
 settngs.json at the end:
 ```json
 {
-  "example": {
+  "Example Group": {
     "hello": "world",
     "verbose": false
   },

settngs/__init__.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import argparse
+import copy
 import json
 import logging
 import pathlib
@@ -12,9 +13,9 @@ from collections import defaultdict
 from collections.abc import Sequence
 from typing import Any
 from typing import Callable
+from typing import cast
 from typing import Dict
 from typing import Generic
-from typing import Literal
 from typing import NoReturn
 from typing import TYPE_CHECKING
 from typing import TypeVar
@@ -84,6 +85,20 @@ else:  # pragma: no cover
     removeprefix = str.removeprefix
 
 
+def _isnamedtupleinstance(x: Any) -> bool:
+    t = type(x)
+    b = t.__bases__
+
+    if len(b) != 1 or b[0] != tuple:
+        return False
+
+    f = getattr(t, '_fields', None)
+    if not isinstance(f, tuple):
+        return False
+
+    return all(isinstance(n, str) for n in f)
+
+
 class Setting:
     def __init__(
         self,
@@ -107,6 +122,9 @@ class Setting:
         exclusive: bool = False,
     ):
         """
+        Attributes:
+        setting_name:     This is the name used to retrieve this Setting object from a `Config` Definitions dictionary.
+                          This only differs from dest when a custom dest is given
 
         Args:
             *names:       Passed directly to argparse
@@ -119,7 +137,8 @@ class Setting:
             required:     Passed directly to argparse
             help:         Passed directly to argparse
             metavar:      Passed directly to argparse, defaults to `dest` upper-cased
-            dest:         This is the name used to retrieve the value from a `Config` object as a dictionary
+            dest:         This is the name used to retrieve the value from a `Config` object as a dictionary.
+                          Default to `setting_name`.
             display_name: This is not used by settngs. This is a human-readable name to be used when generating a GUI.
                           Defaults to `dest`.
             cmdline:      If this setting can be set via the commandline
@@ -133,7 +152,7 @@ class Setting:
             raise ValueError('names must be specified')
         # We prefix the destination name used by argparse so that there are no conflicts
         # Argument names will still cause an exception if there is a conflict e.g. if '-f' is defined twice
-        self.internal_name, dest, flag = self.get_dest(group, names, dest)
+        self.internal_name, setting_name, dest, self.flag = self.get_dest(group, names, dest)
         args: Sequence[str] = names
 
         # We then also set the metavar so that '--config' in the group runtime shows as 'CONFIG' instead of 'RUNTIME_CONFIG'
@@ -141,10 +160,9 @@ class Setting:
             metavar = dest.upper()
 
         # If we are not a flag, no '--' or '-' in front
-        # we prefix the first name with the group as argparse sets dest to args[0]
-        # I believe internal name may be able to be used here
-        if not flag:
-            args = tuple((f'{group}_{names[0]}'.lstrip('_'), *names[1:]))
+        # we use internal_name as argparse sets dest to args[0]
+        if not self.flag:
+            args = tuple((self.internal_name, *names[1:]))
 
         self.action = action
         self.nargs = nargs
@@ -156,6 +174,7 @@ class Setting:
         self.help = help
         self.metavar = metavar
         self.dest = dest
+        self.setting_name = setting_name
         self.cmdline = cmdline
         self.file = file
         self.argparse_args = args
@@ -173,7 +192,7 @@ class Setting:
             'required': required,
             'help': help,
             'metavar': metavar,
-            'dest': self.internal_name if flag else None,
+            'dest': self.internal_name if self.flag else None,
         }
 
     def __str__(self) -> str:  # pragma: no cover
@@ -187,12 +206,19 @@ class Setting:
             return NotImplemented
         return self.__dict__ == other.__dict__
 
-    def _guess_type(self) -> type | Literal['Any'] | None:
+    def _guess_type(self) -> type | str | None:
         if self.type is None and self.action is None:
             if self.cmdline:
+                if self.nargs in ('+', '*') or isinstance(self.nargs, int) and self.nargs > 1:
+                    return List[str]
                 return str
             else:
                 if not self.cmdline and self.default is not None:
+                    if not isinstance(self.default, str) and not _isnamedtupleinstance(self.default) and isinstance(self.default, Sequence) and self.default and self.default[0]:
+                        try:
+                            return cast(type, type(self.default)[type(self.default[0])])
+                        except Exception:
+                            ...
                     return type(self.default)
                 return 'Any'
 
@@ -201,9 +227,15 @@ class Setting:
 
         if self.type is not None:
             type_hints = typing.get_type_hints(self.type)
-            if 'return' in type_hints and isinstance(type_hints['return'], type):
-                return type_hints['return']
+            if 'return' in type_hints:
+                t: type | str = type_hints['return']
+                return t
             if self.default is not None:
+                if not isinstance(self.default, str) and not _isnamedtupleinstance(self.default) and isinstance(self.default, Sequence) and self.default and self.default[0]:
+                    try:
+                        return cast(type, type(self.default)[type(self.default[0])])
+                    except Exception:
+                        ...
                 return type(self.default)
             return 'Any'
 
@@ -226,27 +258,30 @@ class Setting:
             return None
         return 'Any'
 
-    def get_dest(self, prefix: str, names: Sequence[str], dest: str | None) -> tuple[str, str, bool]:
-        dest_name = None
+    def get_dest(self, prefix: str, names: Sequence[str], dest: str | None) -> tuple[str, str, str, bool]:
+        setting_name = None
         flag = False
 
+        prefix = sanitize_name(prefix)
         for n in names:
             if n.startswith('--'):
                 flag = True
-                dest_name = sanitize_name(n)
+                setting_name = sanitize_name(n)
                 break
             if n.startswith('-'):
                 flag = True
 
-        if dest_name is None:
-            dest_name = names[0]
+        if setting_name is None:
+            setting_name = names[0]
         if dest:
             dest_name = dest
+        else:
+            dest_name = setting_name
         if not dest_name.isidentifier():
             raise Exception(f'Cannot use {dest_name} in a namespace')
 
-        internal_name = f'{prefix}_{dest_name}'.lstrip('_')
-        return internal_name, dest_name, flag
+        internal_name = f'{prefix}__{dest_name}'.lstrip('_')
+        return internal_name, setting_name, dest_name, flag
 
     def filter_argparse_kwargs(self) -> dict[str, Any]:
         return {k: v for k, v in self.argparse_kwargs.items() if v is not None}
@@ -255,6 +290,11 @@ class Setting:
         return self.argparse_args, self.filter_argparse_kwargs()
 
 
+class TypedNS:
+    def __init__(self) -> None:
+        raise TypeError('TypedNS cannot be instantiated')
+
+
 class Group(NamedTuple):
     persistent: bool
     v: dict[str, Setting]
@@ -263,7 +303,7 @@ class Group(NamedTuple):
 Values = Dict[str, Dict[str, Any]]
 Definitions = Dict[str, Group]
 
-T = TypeVar('T', Values, Namespace)
+T = TypeVar('T', bound=Union[Values, Namespace, TypedNS])
 
 
 class Config(NamedTuple, Generic[T]):
@@ -273,47 +313,71 @@ class Config(NamedTuple, Generic[T]):
 
 if TYPE_CHECKING:
     ArgParser = Union[argparse._MutuallyExclusiveGroup, argparse._ArgumentGroup, argparse.ArgumentParser]
-    ns = Namespace | Config[T] | None
+    ns = Namespace | TypedNS | Config[T] | None
 
 
 def generate_ns(definitions: Definitions) -> str:
-    imports = ['from __future__ import annotations', 'import typing', 'import settngs']
-    ns = 'class settngs_namespace(settngs.Namespace):\n'
-    types = []
-    for group_name, group in definitions.items():
-        for setting_name, setting in group.v.items():
+    initial_imports = ['from __future__ import annotations', '', 'import settngs', '']
+    imports: Sequence[str] | set[str]
+    imports = set()
+
+    attributes = []
+    for group in definitions.values():
+        for setting in group.v.values():
             t = setting._guess_type()
             if t is None:
                 continue
+            # Default to any
             type_name = 'Any'
+
+            # Take a string as is
             if isinstance(t, str):
                 type_name = t
-            elif type(t) == types_GenericAlias:
+            # Handle generic aliases eg dict[str, str] instead of dict
+            elif isinstance(t, types_GenericAlias):
                 type_name = str(t)
+            # Handle standard type objects
             elif isinstance(t, type):
                 type_name = t.__name__
+                # Builtin types don't need an import
                 if t.__module__ != 'builtins':
-                    imports.append(f'import {t.__module__}')
+                    imports.add(f'import {t.__module__}')
+                    # Use the full imported name
                     type_name = t.__module__ + '.' + type_name
+
+            # Expand Any to typing.Any
             if type_name == 'Any':
                 type_name = 'typing.Any'
 
-            types.append(f'    {setting.internal_name}: {type_name}')
-        if types and types[-1] != '':
-            types.append('')
+            attribute = f'    {setting.internal_name}: {type_name}'
+            if attribute not in attributes:
+                attributes.append(attribute)
+        # Add a blank line between groups
+        if attributes and attributes[-1] != '':
+            attributes.append('')
 
-    if not types or all(x == '' for x in types):
+    ns = 'class settngs_namespace(settngs.TypedNS):\n'
+    # Add a '...' expression if there are no attributes
+    if not attributes or all(x == '' for x in attributes):
         ns += '    ...\n'
-        types = ['']
+        attributes = ['']
 
-    return '\n'.join(imports) + '\n\n' + ns + '\n'.join(types)
+    # Add the tying import before extra imports
+    if 'typing.' in '\n'.join(attributes):
+        initial_imports.append('import typing')
+
+    # Remove the possible duplicate typing import
+    imports = sorted(list(imports - {'import typing'}))
+
+    # Merge the imports the ns class definition and the attributes
+    return '\n'.join(initial_imports + imports) + '\n\n\n' + ns + '\n'.join(attributes)
 
 
 def sanitize_name(name: str) -> str:
     return re.sub('[' + re.escape(' -_,.!@#$%^&*(){}[]\',."<>;:') + ']+', '_', name).strip('_')
 
 
-def get_option(options: Values | Namespace, setting: Setting) -> tuple[Any, bool]:
+def get_option(options: Values | Namespace | TypedNS, setting: Setting) -> tuple[Any, bool]:
     """
     Helper function to retrieve the value for a setting and if the current value is the default value
 
@@ -337,7 +401,7 @@ def get_options(config: Config[T], group: str) -> dict[str, Any]:
         group: The name of the group to retrieve
     """
     if isinstance(config[0], dict):
-        values = config[0].get(group, {}).copy()
+        values: dict[str, Any] = config[0].get(group, {}).copy()
     else:
         internal_names = {x.internal_name: x for x in config[1][group].v.values()}
         values = {}
@@ -347,11 +411,34 @@ def get_options(config: Config[T], group: str) -> dict[str, Any]:
                 if name in internal_names:
                     values[internal_names[name].dest] = value
                 else:
-                    values[removeprefix(name, f'{group}_')] = value
-
+                    values[removeprefix(name, f'{group}').lstrip('_')] = value
     return values
 
 
+def get_groups(values: Values | Namespace | TypedNS) -> list[str]:
+    if isinstance(values, dict):
+        return [x[0] for x in values.items() if isinstance(x[1], dict)]
+    if isinstance(values, Namespace):
+        groups = set()
+        for name in values.__dict__:
+            if '__' in name:
+                group, _, _ = name.partition('__')
+                groups.add(group.replace('_', ' '))
+            else:
+                groups.add('')
+        return list(groups)
+    return []
+
+
+def _get_internal_definitions(config: Config[T], persistent: bool) -> Definitions:
+    definitions = copy.deepcopy(dict(config.definitions))
+    if persistent:
+        for group_name in get_groups(config.values):
+            if group_name not in definitions:
+                definitions[group_name] = Group(True, {})
+    return defaultdict(lambda: Group(False, {}), definitions)
+
+
 def normalize_config(
     config: Config[T],
     file: bool = False,
@@ -369,33 +456,35 @@ def normalize_config(
         file: Include file options
         cmdline: Include cmdline options
         default: Include default values in the returned Config object
-        persistent: Include unknown keys in persistent groups
+        persistent: Include unknown keys in persistent groups and unknown groups
     """
 
     if not file and not cmdline:
         raise ValueError('Invalid parameters: you must set either file or cmdline to True')
 
     normalized: Values = {}
-    options, definitions = config
+    options = config.values
+    definitions = _get_internal_definitions(config=config, persistent=persistent)
     for group_name, group in definitions.items():
         group_options = {}
         if group.persistent and persistent:
-            group_options = get_options(config, group_name)
+            group_options = get_options(Config(options, definitions), group_name)
         for setting_name, setting in group.v.items():
             if (setting.cmdline and cmdline) or (setting.file and file):
                 # Ensures the option exists with the default if not already set
                 value, is_default = get_option(options, setting)
                 if not is_default or default:
                     # User has set a custom value or has requested the default value
-                    group_options[setting_name] = value
-                elif setting_name in group_options:
+                    group_options[setting.dest] = value
+                elif setting.dest in group_options:
                     # default values have been requested to be removed
-                    del group_options[setting_name]
-            elif setting_name in group_options:
+                    del group_options[setting.dest]
+            elif setting.dest in group_options:
                 # Setting type (file or cmdline) has not been requested and should be removed for persistent groups
-                del group_options[setting_name]
+                del group_options[setting.dest]
         normalized[group_name] = group_options
-    return Config(normalized, definitions)
+
+    return Config(normalized, config.definitions)
 
 
 def parse_file(definitions: Definitions, filename: pathlib.Path) -> tuple[Config[Values], bool]:
@@ -438,7 +527,7 @@ def clean_config(
         file: Include file options
         cmdline: Include cmdline options
         default: Include default values in the returned Config object
-        persistent: Include unknown keys in persistent groups
+        persistent: Include unknown keys in persistent groups and unknown groups
     """
 
     cleaned, _ = normalize_config(config, file=file, cmdline=cmdline, default=default, persistent=persistent)
@@ -464,21 +553,22 @@ def get_namespace(
         file: Include file options
         cmdline: Include cmdline options
         default: Include default values in the returned Config object
-        persistent: Include unknown keys in persistent groups
+        persistent: Include unknown keys in persistent groups and unknown groups
     """
-
     if not file and not cmdline:
         raise ValueError('Invalid parameters: you must set either file or cmdline to True')
 
-    if isinstance(config.values, Namespace):
-        cfg = normalize_config(config, file=file, cmdline=cmdline, default=default, persistent=persistent)
-        options, definitions = cfg
+    options: Values
+    definitions = _get_internal_definitions(config=config, persistent=persistent)
+    if isinstance(config.values, dict):
+        options = config.values
     else:
-        options, definitions = config
+        cfg = normalize_config(config, file=file, cmdline=cmdline, default=default, persistent=persistent)
+        options = cfg.values
     namespace = Namespace()
     for group_name, group in definitions.items():
 
-        group_options = get_options(config, group_name)
+        group_options = get_options(Config(options, definitions), group_name)
         if group.persistent and persistent:
             for name, value in group_options.items():
                 if name in group.v:
@@ -487,7 +577,7 @@ def get_namespace(
                     internal_name = group.v[name].internal_name
                 else:
                     setting_file = setting_cmdline = True
-                    internal_name, is_default = f'{group_name}_' + sanitize_name(name), None
+                    internal_name, is_default = f'{group_name}__' + sanitize_name(name), None
 
                 if ((setting_cmdline and cmdline) or (setting_file and file)) and (not is_default or default):
                     setattr(namespace, internal_name, value)
@@ -499,7 +589,7 @@ def get_namespace(
                 if not is_default or default:
                     # User has set a custom value or has requested the default value
                     setattr(namespace, setting.internal_name, value)
-    return Config(namespace, definitions)
+    return Config(namespace, config.definitions)
 
 
 def save_file(
@@ -548,8 +638,11 @@ def create_argparser(definitions: Definitions, description: str, epilog: str) ->
                         else:
                             groups[setting.group] = argparser.add_argument_group(setting.group)
 
-                    # hard coded exception for files
-                    if not (setting.group == 'runtime' and setting.nargs == '*'):
+                    # Hard coded exception for positional arguments
+                    # Ensures that the option shows at the top of the help output
+                    if 'runtime' in setting.group.casefold() and setting.nargs == '*' and not setting.flag:
+                        current_group = argparser
+                    else:
                         current_group = groups[setting.group]
                 current_group.add_argument(*argparse_args, **argparse_kwargs)
     return argparser
@@ -573,7 +666,7 @@ def parse_cmdline(
         args: Passed to argparse.ArgumentParser.parse_args
         config: The Config or Namespace object to use as a Namespace passed to argparse.ArgumentParser.parse_args
     """
-    namespace = None
+    namespace: Namespace | TypedNS | None = None
     if isinstance(config, Config):
         if isinstance(config.values, Namespace):
             namespace = config.values
@@ -581,6 +674,7 @@ def parse_cmdline(
             namespace = get_namespace(config, file=True, cmdline=True, default=False)[0]
     else:
         namespace = config
+
     argparser = create_argparser(definitions, description, epilog)
     ns = argparser.parse_args(args, namespace=namespace)
 
@@ -624,14 +718,20 @@ class Manager:
         self.description = description
         self.epilog = epilog
 
+        self.definitions: Definitions
         if isinstance(definitions, Config):
-            self.definitions = definitions.definitions
+            self.definitions = defaultdict(lambda: Group(False, {}), dict(definitions.definitions) or {})
         else:
-            self.definitions = defaultdict(lambda: Group(False, {}), definitions or {})
+            self.definitions = defaultdict(lambda: Group(False, {}), dict(definitions or {}))
 
         self.exclusive_group = False
         self.current_group_name = ''
 
+    def _get_config(self, c: T | Config[T]) -> Config[T]:
+        if not isinstance(c, Config):
+            return Config(c, self.definitions)
+        return c
+
     def generate_ns(self) -> str:
         return generate_ns(self.definitions)
 
@@ -640,8 +740,9 @@ class Manager:
 
     def add_setting(self, *args: Any, **kwargs: Any) -> None:
         """Passes all arguments through to `Setting`, `group` and `exclusive` are already set"""
+
         setting = Setting(*args, **kwargs, group=self.current_group_name, exclusive=self.exclusive_group)
-        self.definitions[self.current_group_name].v[setting.dest] = setting
+        self.definitions[self.current_group_name].v[setting.setting_name] = setting
 
     def add_group(self, name: str, group: Callable[[Manager], None], exclusive_group: bool = False) -> None:
         """
@@ -652,6 +753,7 @@ class Manager:
             group: A function that registers individual options using :meth:`add_setting`
             exclusive_group: If this group is an argparse exclusive group
         """
+
         if self.current_group_name != '':
             raise ValueError('Sub groups are not allowed')
         self.current_group_name = name
@@ -670,6 +772,7 @@ class Manager:
             group: A function that registers individual options using :meth:`add_setting`
             exclusive_group: If this group is an argparse exclusive group
         """
+
         if self.current_group_name != '':
             raise ValueError('Sub groups are not allowed')
         self.current_group_name = name
@@ -702,9 +805,7 @@ class Manager:
             cmdline: Include cmdline options
         """
 
-        if not isinstance(config, Config):
-            config = Config(config, self.definitions)
-        return clean_config(config, file=file, cmdline=cmdline)
+        return clean_config(self._get_config(config), file=file, cmdline=cmdline)
 
     def normalize_config(
         self,
@@ -724,13 +825,11 @@ class Manager:
             file: Include file options
             cmdline: Include cmdline options
             default: Include default values in the returned Config object
-            persistent: Include unknown keys in persistent groups
+            persistent: Include unknown keys in persistent groups and unknown groups
         """
 
-        if not isinstance(config, Config):
-            config = Config(config, self.definitions)
         return normalize_config(
-            config=config,
+            config=self._get_config(config),
             file=file,
             cmdline=cmdline,
             default=default,
@@ -739,7 +838,7 @@ class Manager:
 
     def get_namespace(
         self,
-        config: Values | Config[Values],
+        config: T | Config[T],
         file: bool = False,
         cmdline: bool = False,
         default: bool = True,
@@ -755,14 +854,12 @@ class Manager:
             file: Include file options
             cmdline: Include cmdline options
             default: Include default values in the returned Config object
-            persistent: Include unknown keys in persistent groups
+            persistent: Include unknown keys in persistent groups and unknown groups
         """
 
-        if isinstance(config, Config):
-            self.definitions = config[1]
-        else:
-            config = Config(config, self.definitions)
-        return get_namespace(config, file=file, cmdline=cmdline, default=default, persistent=persistent)
+        return get_namespace(
+            self._get_config(config), file=file, cmdline=cmdline, default=default, persistent=persistent,
+        )
 
     def parse_file(self, filename: pathlib.Path) -> tuple[Config[Values], bool]:
         """
@@ -773,6 +870,7 @@ class Manager:
         Args:
             filename: A pathlib.Path object to read a JSON dictionary from
         """
+
         return parse_file(filename=filename, definitions=self.definitions)
 
     def save_file(self, config: T | Config[T], filename: pathlib.Path) -> bool:
@@ -785,9 +883,8 @@ class Manager:
             config: The options to save to a json dictionary
             filename: A pathlib.Path object to save the json dictionary to
         """
-        if not isinstance(config, Config):
-            config = Config(config, self.definitions)
-        return save_file(config, filename=filename)
+
+        return save_file(self._get_config(config), filename=filename)
 
     def parse_cmdline(self, args: list[str] | None = None, config: ns[T] = None) -> Config[Values]:
         """
@@ -815,11 +912,12 @@ class Manager:
 
 __all__ = [
     'Setting',
+    'TypedNS',
     'Group',
     'Values',
     'Definitions',
     'Config',
-    'generate_settings',
+    'generate_ns',
     'sanitize_name',
     'get_option',
     'get_options',
@@ -866,7 +964,7 @@ def _main(args: list[str] | None = None) -> None:
     settings_path = pathlib.Path('./settings.json')
     manager = Manager(description='This is an example', epilog='goodbye!')
 
-    manager.add_group('example', example_group)
+    manager.add_group('Example Group', example_group)
     manager.add_persistent_group('persistent', persistent_group)
 
     file_config, success = manager.parse_file(settings_path)
@@ -875,14 +973,14 @@ def _main(args: list[str] | None = None) -> None:
     merged_config = manager.parse_cmdline(args=args, config=file_namespace)
     merged_namespace = manager.get_namespace(merged_config, file=True, cmdline=True)
 
-    print(f'Hello {merged_config.values["example"]["hello"]}')  # noqa: T201
-    if merged_namespace.values.example_save:
+    print(f'Hello {merged_config.values["Example Group"]["hello"]}')  # noqa: T201
+    if merged_namespace.values.Example_Group__save:
         if manager.save_file(merged_config, settings_path):
             print(f'Successfully saved settings to {settings_path}')  # noqa: T201
-        else:
+        else:  # pragma: no cover
             print(f'Failed saving settings to a {settings_path}')  # noqa: T201
-    if merged_namespace.values.example_verbose:
-        print(f'{merged_namespace.values.example_verbose=}')  # noqa: T201
+    if merged_namespace.values.Example_Group__verbose:
+        print(f'{merged_namespace.values.Example_Group__verbose=}')  # noqa: T201
 
 
 if __name__ == '__main__':

setup.cfg

@@ -90,6 +90,7 @@ fail_under = 95
 [mypy]
 check_untyped_defs = true
 disallow_any_generics = true
+warn_return_any = true
 disallow_incomplete_defs = true
 disallow_untyped_defs = true
 no_implicit_optional = true
@@ -97,7 +98,9 @@ warn_redundant_casts = true
 warn_unused_ignores = true
 
 [mypy-testing.*]
+warn_return_any = false
 disallow_untyped_defs = false
 
 [mypy-tests.*]
+warn_return_any = false
 disallow_untyped_defs = false

testing/settngs.py

@@ -15,52 +15,52 @@ example: list[tuple[list[str], str, str]] = [
     (
         ['--hello', 'lordwelch', '-s'],
         'Hello lordwelch\nSuccessfully saved settings to settings.json\n',
-        '{\n  "example": {\n    "hello": "lordwelch",\n    "verbose": false\n  },\n  "persistent": {\n    "test": false\n  }\n}\n',
+        '{\n  "Example Group": {\n    "hello": "lordwelch",\n    "verbose": false\n  },\n  "persistent": {\n    "test": false\n  }\n}\n',
     ),
     (
         [],
         'Hello lordwelch\n',
-        '{\n  "example": {\n    "hello": "lordwelch",\n    "verbose": false\n  },\n  "persistent": {\n    "test": false\n  }\n}\n',
+        '{\n  "Example Group": {\n    "hello": "lordwelch",\n    "verbose": false\n  },\n  "persistent": {\n    "test": false\n  }\n}\n',
     ),
     (
         ['-v'],
-        'Hello lordwelch\nmerged_namespace.values.example_verbose=True\n',
-        '{\n  "example": {\n    "hello": "lordwelch",\n    "verbose": false\n  },\n  "persistent": {\n    "test": false\n  }\n}\n',
+        'Hello lordwelch\nmerged_namespace.values.Example_Group__verbose=True\n',
+        '{\n  "Example Group": {\n    "hello": "lordwelch",\n    "verbose": false\n  },\n  "persistent": {\n    "test": false\n  }\n}\n',
     ),
     (
         ['-v', '-s'],
-        'Hello lordwelch\nSuccessfully saved settings to settings.json\nmerged_namespace.values.example_verbose=True\n',
-        '{\n  "example": {\n    "hello": "lordwelch",\n    "verbose": true\n  },\n  "persistent": {\n    "test": false\n  }\n}\n',
+        'Hello lordwelch\nSuccessfully saved settings to settings.json\nmerged_namespace.values.Example_Group__verbose=True\n',
+        '{\n  "Example Group": {\n    "hello": "lordwelch",\n    "verbose": true\n  },\n  "persistent": {\n    "test": false\n  }\n}\n',
     ),
     (
         [],
-        'Hello lordwelch\nmerged_namespace.values.example_verbose=True\n',
-        '{\n  "example": {\n    "hello": "lordwelch",\n    "verbose": true\n  },\n  "persistent": {\n    "test": false\n  }\n}\n',
+        'Hello lordwelch\nmerged_namespace.values.Example_Group__verbose=True\n',
+        '{\n  "Example Group": {\n    "hello": "lordwelch",\n    "verbose": true\n  },\n  "persistent": {\n    "test": false\n  }\n}\n',
     ),
     (
         ['manual settings.json'],
-        'Hello lordwelch\nmerged_namespace.values.example_verbose=True\n',
-        '{\n  "example": {\n    "hello": "lordwelch",\n    "verbose": true\n  },\n  "persistent": {\n    "test": false,\n    "hello": "world"\n  }\n}\n',
+        'Hello lordwelch\nmerged_namespace.values.Example_Group__verbose=True\n',
+        '{\n  "Example Group": {\n    "hello": "lordwelch",\n    "verbose": true\n  },\n  "persistent": {\n    "test": false,\n    "hello": "world"\n  }\n}\n',
     ),
     (
         ['--no-verbose', '-t'],
         'Hello lordwelch\n',
-        '{\n  "example": {\n    "hello": "lordwelch",\n    "verbose": true\n  },\n  "persistent": {\n    "test": false,\n    "hello": "world"\n  }\n}\n',
+        '{\n  "Example Group": {\n    "hello": "lordwelch",\n    "verbose": true\n  },\n  "persistent": {\n    "test": false,\n    "hello": "world"\n  }\n}\n',
     ),
     (
         ['--no-verbose', '-s', '-t'],
         'Hello lordwelch\nSuccessfully saved settings to settings.json\n',
-        '{\n  "example": {\n    "hello": "lordwelch",\n    "verbose": false\n  },\n  "persistent": {\n    "test": true,\n    "hello": "world"\n  }\n}\n',
+        '{\n  "Example Group": {\n    "hello": "lordwelch",\n    "verbose": false\n  },\n  "persistent": {\n    "test": true,\n    "hello": "world"\n  }\n}\n',
     ),
     (
         ['--hello', 'world', '--no-verbose', '--no-test', '-s'],
         'Hello world\nSuccessfully saved settings to settings.json\n',
-        '{\n  "example": {\n    "hello": "world",\n    "verbose": false\n  },\n  "persistent": {\n    "test": false,\n    "hello": "world"\n  }\n}\n',
+        '{\n  "Example Group": {\n    "hello": "world",\n    "verbose": false\n  },\n  "persistent": {\n    "test": false,\n    "hello": "world"\n  }\n}\n',
     ),
     (
         [],
         'Hello world\n',
-        '{\n  "example": {\n    "hello": "world",\n    "verbose": false\n  },\n  "persistent": {\n    "test": false,\n    "hello": "world"\n  }\n}\n',
+        '{\n  "Example Group": {\n    "hello": "world",\n    "verbose": false\n  },\n  "persistent": {\n    "test": false,\n    "hello": "world"\n  }\n}\n',
     ),
 ]
 success = [
@@ -77,13 +77,15 @@ success = [
             'cmdline': True,
             'const': None,
             'default': None,
+            'setting_name': 'test_setting',  # dest is calculated by Setting and is not used by argparse
             'dest': 'test_setting',  # dest is calculated by Setting and is not used by argparse
             'display_name': 'test_setting',  # defaults to dest
             'exclusive': False,
             'file': True,
+            'flag': True,
             'group': 'tst',
             'help': None,
-            'internal_name': 'tst_test_setting',  # Should almost always be "{group}_{dest}"
+            'internal_name': 'tst__test_setting',  # Should almost always be "{group}__{dest}"
             'metavar': 'TEST_SETTING',  # Set manually so argparse doesn't use TST_TEST
             'nargs': None,
             'required': None,
@@ -94,7 +96,7 @@ success = [
                 'choices': None,
                 'const': None,
                 'default': None,
-                'dest': 'tst_test_setting',
+                'dest': 'tst__test_setting',
                 'help': None,
                 'metavar': 'TEST_SETTING',
                 'nargs': None,
@@ -117,13 +119,15 @@ success = [
             'cmdline': True,
             'const': None,
             'default': None,
+            'setting_name': 'test',  # setting_name is calculated by Setting and is not used by argparse
             'dest': 'testing',  # dest is calculated by Setting and is not used by argparse
             'display_name': 'testing',  # defaults to dest
             'exclusive': False,
             'file': True,
+            'flag': True,
             'group': 'tst',
             'help': None,
-            'internal_name': 'tst_testing',  # Should almost always be "{group}_{dest}"
+            'internal_name': 'tst__testing',  # Should almost always be "{group}__{dest}"
             'metavar': 'TESTING',  # Set manually so argparse doesn't use TST_TEST
             'nargs': None,
             'required': None,
@@ -134,7 +138,7 @@ success = [
                 'choices': None,
                 'const': None,
                 'default': None,
-                'dest': 'tst_testing',
+                'dest': 'tst__testing',
                 'help': None,
                 'metavar': 'TESTING',
                 'nargs': None,
@@ -156,13 +160,15 @@ success = [
             'cmdline': True,
             'const': None,
             'default': None,
+            'setting_name': 'test',  # dest is calculated by Setting and is not used by argparse
             'dest': 'test',  # dest is calculated by Setting and is not used by argparse
             'display_name': 'test',  # defaults to dest
             'exclusive': False,
             'file': True,
+            'flag': True,
             'group': 'tst',
             'help': None,
-            'internal_name': 'tst_test',  # Should almost always be "{group}_{dest}"
+            'internal_name': 'tst__test',  # Should almost always be "{group}__{dest}"
             'metavar': 'TEST',  # Set manually so argparse doesn't use TST_TEST
             'nargs': None,
             'required': None,
@@ -173,7 +179,7 @@ success = [
                 'choices': None,
                 'const': None,
                 'default': None,
-                'dest': 'tst_test',
+                'dest': 'tst__test',
                 'help': None,
                 'metavar': 'TEST',
                 'nargs': None,
@@ -196,13 +202,15 @@ success = [
             'cmdline': True,
             'const': None,
             'default': None,
+            'setting_name': 'test',  # dest is calculated by Setting and is not used by argparse
             'dest': 'test',  # dest is calculated by Setting and is not used by argparse
             'display_name': 'test',  # defaults to dest
             'exclusive': False,
             'file': True,
+            'flag': True,
             'group': 'tst',
             'help': None,
-            'internal_name': 'tst_test',  # Should almost always be "{group}_{dest}"
+            'internal_name': 'tst__test',  # Should almost always be "{group}__{dest}"
             'metavar': None,  # store_true does not get a metavar
             'nargs': None,
             'required': None,
@@ -213,7 +221,7 @@ success = [
                 'choices': None,
                 'const': None,
                 'default': None,
-                'dest': 'tst_test',
+                'dest': 'tst__test',
                 'help': None,
                 'metavar': None,
                 'nargs': None,
@@ -235,13 +243,15 @@ success = [
             'cmdline': True,
             'const': None,
             'default': None,
+            'setting_name': 'test',
             'dest': 'test',
             'display_name': 'test',  # defaults to dest
             'exclusive': False,
             'file': True,
+            'flag': True,
             'group': 'tst',
             'help': None,
-            'internal_name': 'tst_test',
+            'internal_name': 'tst__test',
             'metavar': 'TEST',
             'nargs': None,
             'required': None,
@@ -252,7 +262,7 @@ success = [
                 'choices': None,
                 'const': None,
                 'default': None,
-                'dest': 'tst_test',
+                'dest': 'tst__test',
                 'help': None,
                 'metavar': 'TEST',
                 'nargs': None,
@@ -274,18 +284,20 @@ success = [
             'cmdline': True,
             'const': None,
             'default': None,
+            'setting_name': 'test',
             'dest': 'test',
             'display_name': 'test',  # defaults to dest
             'exclusive': False,
             'file': True,
+            'flag': False,
             'group': 'tst',
             'help': None,
-            'internal_name': 'tst_test',
+            'internal_name': 'tst__test',
             'metavar': 'TEST',
             'nargs': None,
             'required': None,
             'type': None,
-            'argparse_args': ('tst_test',),
+            'argparse_args': ('tst__test',),
             'argparse_kwargs': {
                 'action': None,
                 'choices': None,
@@ -311,10 +323,12 @@ success = [
             'cmdline': True,
             'const': None,
             'default': None,
+            'setting_name': 'test',
             'dest': 'test',
             'display_name': 'test',  # defaults to dest
             'exclusive': False,
             'file': True,
+            'flag': True,
             'group': '',
             'help': None,
             'internal_name': 'test',  # No group, leading _ is stripped

tests/settngs_test.py

@@ -6,6 +6,7 @@ import json
 import pathlib
 import sys
 from collections import defaultdict
+from textwrap import dedent
 from typing import Generator
 
 import pytest
@@ -17,10 +18,40 @@ from testing.settngs import failure
 from testing.settngs import success
 
 
-if sys.version_info < (3, 9):  # pragma: no cover
-    from typing import List
-else:
+if sys.version_info >= (3, 10):  # pragma: no cover
     List = list
+    help_output = '''\
+usage: __main__.py [-h] [TEST ...]
+
+positional arguments:
+  TEST
+
+options:
+  -h, --help  show this help message and exit
+'''
+elif sys.version_info < (3, 9):  # pragma: no cover
+    from typing import List
+    help_output = '''\
+usage: __main__.py [-h] [TEST [TEST ...]]
+
+positional arguments:
+  TEST
+
+optional arguments:
+  -h, --help  show this help message and exit
+'''
+
+else:  # pragma: no cover
+    List = list
+    help_output = '''\
+usage: __main__.py [-h] [TEST ...]
+
+positional arguments:
+  TEST
+
+optional arguments:
+  -h, --help  show this help message and exit
+'''
 
 
 @pytest.fixture
@@ -63,6 +94,55 @@ def test_add_setting(settngs_manager):
     assert settngs_manager.add_setting('--test') is None
 
 
+def test_add_setting_invalid_name(settngs_manager):
+    with pytest.raises(Exception, match='Cannot use test¥ in a namespace'):
+        assert settngs_manager.add_setting('--test¥') is None
+
+
+def test_sub_group(settngs_manager):
+    with pytest.raises(Exception, match='Sub groups are not allowed'):
+        settngs_manager.add_group('tst', lambda parser: parser.add_group('tst', lambda parser: parser.add_setting('--test2', default='hello')))
+
+
+def test_sub_persistent_group(settngs_manager):
+    with pytest.raises(Exception, match='Sub groups are not allowed'):
+        settngs_manager.add_persistent_group('tst', lambda parser: parser.add_persistent_group('tst', lambda parser: parser.add_setting('--test2', default='hello')))
+
+
+def test_redefine_persistent_group(settngs_manager):
+    settngs_manager.add_group('tst', lambda parser: parser.add_setting('--test2', default='hello'))
+    with pytest.raises(Exception, match='Group already exists and is not persistent'):
+        settngs_manager.add_persistent_group('tst', None)
+
+
+def test_exclusive_group(settngs_manager):
+    settngs_manager.add_group('tst', lambda parser: parser.add_setting('--test', default='hello'), exclusive_group=True)
+    settngs_manager.create_argparser()
+    args = settngs_manager.argparser.parse_args(['--test', 'never'])
+    assert args.tst__test == 'never'
+
+    with pytest.raises(SystemExit):
+        settngs_manager.add_group('tst', lambda parser: parser.add_setting('--test2', default='hello'), exclusive_group=True)
+        settngs_manager.create_argparser()
+        args = settngs_manager.argparser.parse_args(['--test', 'never', '--test2', 'never'])
+
+
+def test_files_group(capsys, settngs_manager):
+    settngs_manager.add_group('runtime', lambda parser: parser.add_setting('test', default='hello', nargs='*'))
+    settngs_manager.create_argparser()
+    settngs_manager.argparser.print_help()
+    captured = capsys.readouterr()
+    assert captured.out == help_output
+
+
+def test_setting_without_group(capsys, settngs_manager):
+    settngs_manager.add_setting('test', default='hello', nargs='*')
+    settngs_manager.create_argparser()
+    settngs_manager.argparser.print_help()
+    captured = capsys.readouterr()
+    assert captured.out == help_output
+
+
 class TestValues:
 
     def test_invalid_normalize(self, settngs_manager):
@@ -81,6 +161,11 @@ class TestValues:
         defaults, _ = settngs_manager.defaults()
         assert defaults['tst']['test'] == 'hello'
 
+    def test_get_defaults_group_space(self, settngs_manager):
+        settngs_manager.add_group('Testing tst', lambda parser: parser.add_setting('--test', default='hello'))
+        defaults, _ = settngs_manager.defaults()
+        assert defaults['Testing tst']['test'] == 'hello'
+
     def test_cmdline_only(self, settngs_manager):
         settngs_manager.add_group('tst', lambda parser: parser.add_setting('--test', default='hello', file=False))
         settngs_manager.add_group('tst2', lambda parser: parser.add_setting('--test2', default='hello', cmdline=False))
@@ -125,6 +210,24 @@ class TestValues:
         assert non_defaults_normalized.values['tst'] == {'test': 'world'}
         assert non_defaults_normalized.values['tst_persistent'] == {'test': 'world'}
 
+    def test_normalize_dest(self, settngs_manager):
+        settngs_manager.add_group('tst', lambda parser: parser.add_setting('--test', default='hello'))
+        settngs_manager.add_group('tst', lambda parser: parser.add_setting('--test2', dest='test', default='hello'))
+        settngs_manager.add_persistent_group('tst_persistent', lambda parser: parser.add_setting('--test', default='hello'))
+
+        defaults = settngs_manager.defaults()
+        defaults_normalized = settngs_manager.normalize_config(defaults, file=True, default=False)
+        assert defaults_normalized.values['tst'] == {}
+        assert defaults_normalized.values['tst_persistent'] == {}
+
+        non_defaults = settngs_manager.defaults()
+        non_defaults.values['tst']['test'] = 'world'
+        non_defaults.values['tst_persistent']['test'] = 'world'
+        non_defaults_normalized = settngs_manager.normalize_config(non_defaults, file=True, default=False)
+
+        assert non_defaults_normalized.values['tst'] == {'test': 'world'}
+        assert non_defaults_normalized.values['tst_persistent'] == {'test': 'world'}
+
     def test_normalize(self, settngs_manager):
         settngs_manager.add_group('tst', lambda parser: parser.add_setting('--test', default='hello'))
         settngs_manager.add_persistent_group('persistent', lambda parser: parser.add_setting('--world', default='world'))
@@ -142,6 +245,29 @@ class TestValues:
         assert normalized['persistent']['hello'] == 'success'
         assert normalized['persistent']['world'] == 'world'
 
+    def test_unknown_group(self):
+        manager = settngs.Manager()
+        manager.add_group('tst', lambda parser: parser.add_setting('--test', default='hello'))
+        manager.add_persistent_group('persistent', lambda parser: parser.add_setting('--world', default='world'))
+
+        manager_unknown = settngs.Manager()
+        manager_unknown.add_group('tst', lambda parser: parser.add_setting('--test', default='hello'))
+        # This manager doesn't know about this group
+        # manager_unknown.add_persistent_group('persistent', lambda parser: parser.add_setting('--world', default='world'))
+
+        defaults = manager.defaults()
+        defaults.values['test'] = 'fail'  # type: ignore[assignment] # Not defined in manager, should be removed
+        defaults.values['persistent']['hello'] = 'success'  # Group is not defined in manager_unknown, should stay
+
+        normalized, _ = manager_unknown.normalize_config(defaults.values, file=True)
+
+        assert 'test' not in normalized
+        assert 'tst' in normalized
+        assert 'test' in normalized['tst']
+        assert normalized['tst']['test'] == 'hello'
+        assert normalized['persistent']['hello'] == 'success'
+        assert normalized['persistent']['world'] == 'world'
+
 
 class TestNamespace:
 
@@ -159,7 +285,12 @@ class TestNamespace:
     def test_get_defaults_group(self, settngs_manager):
         settngs_manager.add_group('tst', lambda parser: parser.add_setting('--test', default='hello'))
         defaults, _ = settngs_manager.get_namespace(settngs_manager.defaults(), file=True, cmdline=True)
-        assert defaults.tst_test == 'hello'
+        assert defaults.tst__test == 'hello'
+
+    def test_get_defaults_group_space(self, settngs_manager):
+        settngs_manager.add_group('Testing tst', lambda parser: parser.add_setting('--test', default='hello'))
+        defaults, _ = settngs_manager.get_namespace(settngs_manager.defaults(), file=True, cmdline=True)
+        assert defaults.Testing_tst__test == 'hello'
 
     def test_cmdline_only(self, settngs_manager):
         settngs_manager.add_group('tst', lambda parser: parser.add_setting('--test', default='hello', file=False))
@@ -168,11 +299,11 @@ class TestNamespace:
         file_normalized, _ = settngs_manager.get_namespace(settngs_manager.normalize_config(settngs_manager.defaults(), file=True), file=True)
         cmdline_normalized, _ = settngs_manager.get_namespace(settngs_manager.normalize_config(settngs_manager.defaults(), cmdline=True), cmdline=True)
 
-        assert 'tst_test' not in file_normalized.__dict__
-        assert 'tst2_test2' in file_normalized.__dict__
+        assert 'tst__test' not in file_normalized.__dict__
+        assert 'tst2__test2' in file_normalized.__dict__
 
-        assert 'tst_test' in cmdline_normalized.__dict__
-        assert 'tst2_test2' not in cmdline_normalized.__dict__
+        assert 'tst__test' in cmdline_normalized.__dict__
+        assert 'tst2__test2' not in cmdline_normalized.__dict__
 
     def test_cmdline_only_persistent_group(self, settngs_manager):
         settngs_manager.add_persistent_group('tst', lambda parser: parser.add_setting('--test', default='hello', file=False))
@@ -181,11 +312,11 @@ class TestNamespace:
         file_normalized, _ = settngs_manager.get_namespace(settngs_manager.normalize_config(settngs_manager.defaults(), file=True), file=True)
         cmdline_normalized, _ = settngs_manager.get_namespace(settngs_manager.normalize_config(settngs_manager.defaults(), cmdline=True), cmdline=True)
 
-        assert 'tst_test' not in file_normalized.__dict__
-        assert 'tst2_test2' in file_normalized.__dict__
+        assert 'tst__test' not in file_normalized.__dict__
+        assert 'tst2__test2' in file_normalized.__dict__
 
-        assert 'tst_test' in cmdline_normalized.__dict__
-        assert 'tst2_test2' not in cmdline_normalized.__dict__
+        assert 'tst__test' in cmdline_normalized.__dict__
+        assert 'tst2__test2' not in cmdline_normalized.__dict__
 
     def test_normalize_defaults(self, settngs_manager):
         settngs_manager.add_group('tst', lambda parser: parser.add_setting('--test', default='hello'))
@@ -197,12 +328,29 @@ class TestNamespace:
         assert defaults_normalized.values.__dict__ == {}
 
         non_defaults = settngs_manager.get_namespace(settngs_manager.defaults(), file=True, cmdline=True)
-        non_defaults.values.tst_test = 'world'
-        non_defaults.values.tst_persistent_test = 'world'
+        non_defaults.values.tst__test = 'world'
+        non_defaults.values.tst_persistent__test = 'world'
         non_defaults_normalized = settngs_manager.get_namespace(settngs_manager.normalize_config(non_defaults, file=True, default=False), file=True, default=False)
 
-        assert non_defaults_normalized.values.tst_test == 'world'
-        assert non_defaults_normalized.values.tst_persistent_test == 'world'
+        assert non_defaults_normalized.values.tst__test == 'world'
+        assert non_defaults_normalized.values.tst_persistent__test == 'world'
+
+    def test_normalize_dest(self, settngs_manager):
+        settngs_manager.add_group('tst', lambda parser: parser.add_setting('--test', default='hello'))
+        settngs_manager.add_group('tst', lambda parser: parser.add_setting('--test2', dest='test', default='hello'))
+        settngs_manager.add_persistent_group('tst_persistent', lambda parser: parser.add_setting('--test', default='hello'))
+
+        defaults = settngs_manager.defaults()
+        defaults_normalized = settngs_manager.get_namespace(settngs_manager.normalize_config(defaults, file=True, default=False), file=True, default=False)
+        assert defaults_normalized.values.__dict__ == {}
+
+        non_defaults = settngs_manager.get_namespace(settngs_manager.defaults(), file=True, cmdline=True)
+        non_defaults.values.tst__test = 'world'
+        non_defaults.values.tst_persistent__test = 'world'
+        non_defaults_normalized = settngs_manager.get_namespace(settngs_manager.normalize_config(non_defaults, file=True, default=False), file=True, default=False)
+
+        assert non_defaults_normalized.values.tst__test == 'world'
+        assert non_defaults_normalized.values.tst_persistent__test == 'world'
 
     def test_normalize(self, settngs_manager):
         settngs_manager.add_group('tst', lambda parser: parser.add_setting('--test', default='hello'))
@@ -210,15 +358,37 @@ class TestNamespace:
 
         defaults = settngs_manager.get_namespace(settngs_manager.defaults(), file=True, cmdline=True)
         defaults.values.test = 'fail'  # Not defined in settngs_manager, should be removed
-        defaults.values.persistent_hello = 'success'  # Not defined in settngs_manager, should stay
+        defaults.values.persistent__hello = 'success'  # Not defined in settngs_manager, should stay
 
         normalized, _ = settngs_manager.get_namespace(settngs_manager.normalize_config(defaults, file=True), file=True)
 
         assert not hasattr(normalized, 'test')
-        assert hasattr(normalized, 'tst_test')
-        assert normalized.tst_test == 'hello'
-        assert normalized.persistent_hello == 'success'
-        assert normalized.persistent_world == 'world'
+        assert hasattr(normalized, 'tst__test')
+        assert normalized.tst__test == 'hello'
+        assert normalized.persistent__hello == 'success'
+        assert normalized.persistent__world == 'world'
+
+    def test_normalize_unknown_group(self, settngs_manager):
+        manager = settngs.Manager()
+        manager.add_group('tst', lambda parser: parser.add_setting('--test', default='hello'))
+        manager.add_persistent_group('persistent', lambda parser: parser.add_setting('--world', default='world'))
+
+        manager_unknown = settngs.Manager()
+        manager_unknown.add_group('tst', lambda parser: parser.add_setting('--test', default='hello'))
+        # This manager doesn't know about this group
+        # manager_unknown.add_persistent_group('persistent', lambda parser: parser.add_setting('--world', default='world'))
+
+        defaults = manager.get_namespace(manager.defaults(), file=True, cmdline=True)
+        defaults.values.test = 'fail'  # Not defined in manager, should be removed
+        defaults.values.persistent__hello = 'success'  # Not defined in manager, should stay
+
+        normalized, _ = manager_unknown.get_namespace(defaults.values, file=True)
+
+        assert not hasattr(normalized, 'test')
+        assert hasattr(normalized, 'tst__test')
+        assert normalized.tst__test == 'hello'
+        assert normalized.persistent__hello == 'success'
+        assert normalized.persistent__world == 'world'
 
 
 def test_get_namespace_with_namespace(settngs_manager):
@@ -230,7 +400,7 @@ def test_get_namespace_with_namespace(settngs_manager):
 def test_get_namespace_group(settngs_manager):
     settngs_manager.add_group('tst', lambda parser: parser.add_setting('--test', default='hello'))
     defaults, _ = settngs_manager.get_namespace(settngs_manager.defaults(), file=True)
-    assert defaults.tst_test == 'hello'
+    assert defaults.tst__test == 'hello'
 
 
 def test_clean_config(settngs_manager):
@@ -261,8 +431,8 @@ def test_parse_cmdline(settngs_manager):
 
 namespaces = (
     lambda definitions: settngs.Config({'tst': {'test': 'fail', 'test2': 'success'}}, definitions),
-    lambda definitions: settngs.Config(argparse.Namespace(tst_test='fail', tst_test2='success'), definitions),
-    lambda definitions: argparse.Namespace(tst_test='fail', tst_test2='success'),
+    lambda definitions: settngs.Config(argparse.Namespace(tst__test='fail', tst__test2='success'), definitions),
+    lambda definitions: argparse.Namespace(tst__test='fail', tst__test2='success'),
 )
 
 
@@ -523,6 +693,7 @@ settings = (
     (lambda parser: parser.add_setting('-t', '--test', action='help'), None),
     (lambda parser: parser.add_setting('-t', '--test', action='version'), None),
     (lambda parser: parser.add_setting('-t', '--test', type=int), 'int'),
+    (lambda parser: parser.add_setting('-t', '--test', nargs='+'), List[str]),
     (lambda parser: parser.add_setting('-t', '--test', type=_typed_function), 'tests.settngs_test.test_type'),
     (lambda parser: parser.add_setting('-t', '--test', type=_untyped_function, default=1), 'int'),
     (lambda parser: parser.add_setting('-t', '--test', type=_untyped_function), 'typing.Any'),
@@ -533,16 +704,21 @@ settings = (
 def test_generate_ns(settngs_manager, set_options, typ):
     settngs_manager.add_group('test', set_options)
 
-    src = '''\
+    src = dedent('''\
     from __future__ import annotations
-import typing
+
     import settngs
-'''
+    ''')
+
+    if 'typing.' in str(typ):
+        src += '\nimport typing'
     if typ == 'tests.settngs_test.test_type':
-        src += 'import tests.settngs_test\n'
-    src += '''
-class settngs_namespace(settngs.Namespace):
-'''
+        src += '\nimport tests.settngs_test'
+    src += dedent('''
+
+
+    class settngs_namespace(settngs.TypedNS):
+    ''')
     if typ is None:
         src += '    ...\n'
     else:
@@ -564,7 +740,7 @@ def test_example(capsys, tmp_path, monkeypatch):
     for args, expected_out, expected_file in example:
         if args == ['manual settings.json']:
             settings_file.unlink()
-            settings_file.write_text('{\n  "example": {\n    "hello": "lordwelch",\n    "verbose": true\n  },\n  "persistent": {\n    "test": false,\n    "hello": "world"\n  }\n}\n')
+            settings_file.write_text('{\n  "Example Group": {\n    "hello": "lordwelch",\n    "verbose": true\n  },\n  "persistent": {\n    "test": false,\n    "hello": "world"\n  }\n}\n')
             i += 1
             continue
         else: