Merge pull request astropy#17546 from eerovaher/config-annotations

Add more type annotations to `config`

astropy/config/configuration.py

@@ -9,6 +9,8 @@
     found at https://configobj.readthedocs.io .
 """
 
+from __future__ import annotations
+
 import contextlib
 import importlib
 import io
@@ -19,6 +21,7 @@
 from inspect import getdoc
 from pathlib import Path
 from textwrap import TextWrapper
+from typing import TYPE_CHECKING
 from warnings import warn
 
 from astropy.extern.configobj import configobj, validate
@@ -27,6 +30,10 @@
 
 from .paths import get_config_dir_path
 
+if TYPE_CHECKING:
+    from collections.abc import Generator
+    from typing import Final
+
 __all__ = (
     "ConfigItem",
     "ConfigNamespace",
@@ -84,7 +91,7 @@ class Conf(_config.ConfigNamespace):
         conf = Conf()
     """
 
-    def __iter__(self):
+    def __iter__(self) -> Generator[str, None, None]:
         for key, val in self.__class__.__dict__.items():
             if isinstance(val, ConfigItem):
                 yield key
@@ -100,19 +107,19 @@ def __str__(self):
     keys = __iter__
     """Iterate over configuration item names."""
 
-    def values(self):
+    def values(self) -> Generator[ConfigItem, None, None]:
         """Iterate over configuration item values."""
         for val in self.__class__.__dict__.values():
             if isinstance(val, ConfigItem):
                 yield val
 
-    def items(self):
+    def items(self) -> Generator[tuple[str, ConfigItem], None, None]:
         """Iterate over configuration item ``(name, value)`` pairs."""
         for key, val in self.__class__.__dict__.items():
             if isinstance(val, ConfigItem):
                 yield key, val
 
-    def help(self, name=None):
+    def help(self, name: str | None = None) -> None:
         """Print info about configuration items.
 
         Parameters
@@ -185,7 +192,7 @@ def reload(self, attr=None):
         for item in self.values():
             item.reload()
 
-    def reset(self, attr=None):
+    def reset(self, attr: str | None = None) -> None:
         """
         Reset a configuration item to its default.
 
@@ -426,13 +433,13 @@ def reload(self):
             baseobj[self.name] = newobj[self.name]
         return baseobj.get(self.name)
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         return (
             f"<{self.__class__.__name__}: name={self.name!r} value={self()!r} at"
             f" 0x{id(self):x}>"
         )
 
-    def __str__(self):
+    def __str__(self) -> str:
         return "\n".join(
             (
                 f"{self.__class__.__name__}: {self.name}",
@@ -529,7 +536,7 @@ def _validate_val(self, val):
 
 # this dictionary stores the primary copy of the ConfigObj's for each
 # root package
-_cfgobjs = {}
+_cfgobjs: Final[dict[str, configobj.ConfigObj]] = {}
 
 
 def get_config_filename(packageormod=None, rootname=None):

astropy/config/paths.py

@@ -3,12 +3,22 @@
 data/cache files used by Astropy should be placed.
 """
 
+from __future__ import annotations
+
 import os
 import shutil
 import sys
 from functools import wraps
 from inspect import cleandoc
 from pathlib import Path
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from collections.abc import Callable
+    from types import TracebackType
+    from typing import Literal, ParamSpec
+
+    P = ParamSpec("P")
 
 __all__ = [
     "get_cache_dir",
@@ -20,7 +30,9 @@
 ]
 
 
-def _get_dir_path(rootname: str, cls: type, fallback: str) -> Path:
+def _get_dir_path(
+    rootname: str, cls: type[_SetTempPath], fallback: Literal["cache", "config"]
+) -> Path:
     # If using set_temp_x, that overrides all
     if (xch := cls._temp_path) is not None:
         path = xch / rootname
@@ -131,36 +143,43 @@ def get_cache_dir(rootname: str = "astropy") -> str:
 
 
 class _SetTempPath:
-    _temp_path = None
-    _default_path_getter = None
+    _temp_path: Path | None = None
+    _default_path_getter: Callable[[str], str]
 
-    def __init__(self, path=None, delete=False):
+    def __init__(
+        self, path: os.PathLike[str] | str | None = None, delete: bool = False
+    ) -> None:
         if path is not None:
             path = Path(path).resolve()
 
         self._path = path
         self._delete = delete
         self._prev_path = self.__class__._temp_path
 
-    def __enter__(self):
+    def __enter__(self) -> str:
         self.__class__._temp_path = self._path
         try:
             return self._default_path_getter("astropy")
         except Exception:
             self.__class__._temp_path = self._prev_path
             raise
 
-    def __exit__(self, *args):
+    def __exit__(
+        self,
+        type: type[BaseException] | None,
+        value: BaseException | None,
+        tb: TracebackType | None,
+    ) -> None:
         self.__class__._temp_path = self._prev_path
 
         if self._delete and self._path is not None:
             shutil.rmtree(self._path)
 
-    def __call__(self, func):
+    def __call__(self, func: Callable[P, object]) -> Callable[P, None]:
         """Implements use as a decorator."""
 
         @wraps(func)
-        def wrapper(*args, **kwargs):
+        def wrapper(*args: P.args, **kwargs: P.kwargs) -> None:
             with self:
                 func(*args, **kwargs)
 
@@ -195,7 +214,7 @@ class set_temp_config(_SetTempPath):
 
     _default_path_getter = staticmethod(get_config_dir)
 
-    def __enter__(self):
+    def __enter__(self) -> str:
         # Special case for the config case, where we need to reset all the
         # cached config objects.  We do keep the cache, since some of it
         # may have been set programmatically rather than be stored in the
@@ -206,13 +225,18 @@ def __enter__(self):
         _cfgobjs.clear()
         return super().__enter__()
 
-    def __exit__(self, *args):
+    def __exit__(
+        self,
+        type: type[BaseException] | None,
+        value: BaseException | None,
+        tb: TracebackType | None,
+    ) -> None:
         from .configuration import _cfgobjs
 
         _cfgobjs.clear()
         _cfgobjs.update(self._cfgobjs_copy)
         del self._cfgobjs_copy
-        super().__exit__(*args)
+        super().__exit__(type, value, tb)
 
 
 class set_temp_cache(_SetTempPath):