Add @final/Final type hints

CHANGES/477.feature

@@ -0,0 +1 @@
+Add ``@final``/``Final`` type hints

Makefile

@@ -35,7 +35,7 @@ black-check:
 	black --check $(SRC)
 
 mypy:
-	mypy yarl tests
+	mypy --show-error-codes yarl tests
 
 lint: flake8 black-check mypy
 

tests/test_url.py

@@ -11,7 +11,7 @@
 def test_inheritance():
     with pytest.raises(TypeError) as ctx:
 
-        class MyURL(URL):
+        class MyURL(URL):  # type: ignore[misc]
             pass
 
     assert (

yarl/__init__.py

@@ -234,7 +234,7 @@ def build(
             return url
 
     def __init_subclass__(cls):
-        raise TypeError("Inheritance a class {!r} from URL " "is forbidden".format(cls))
+        raise TypeError("Inheritance a class {!r} from URL is forbidden".format(cls))
 
     def __str__(self):
         val = self._val

yarl/__init__.pyi

@@ -1,36 +1,36 @@
 from typing import overload, Any, Tuple, Optional, Mapping, Union, Sequence, Type
-from typing_extensions import TypedDict
+from typing_extensions import TypedDict, Final, final
 import multidict
 from functools import _CacheInfo
 
 _QueryVariable = Union[str, int]
 _Query = Union[
     None, str, Mapping[str, _QueryVariable], Sequence[Tuple[str, _QueryVariable]]
 ]
-
+@final
 class URL:
-    scheme: str
-    raw_user: str
-    user: Optional[str]
-    raw_password: Optional[str]
-    password: Optional[str]
-    raw_host: Optional[str]
-    host: Optional[str]
-    port: Optional[int]
-    raw_path: str
-    path: str
-    raw_query_string: str
-    query_string: str
-    path_qs: str
-    raw_path_qs: str
-    raw_fragment: str
-    fragment: str
-    query: multidict.MultiDict[str]
-    raw_name: str
-    name: str
-    raw_parts: Tuple[str, ...]
-    parts: Tuple[str, ...]
-    parent: URL
+    scheme: Final[str]
+    raw_user: Final[str]
+    user: Final[Optional[str]]
+    raw_password: Final[Optional[str]]
+    password: Final[Optional[str]]
+    raw_host: Final[Optional[str]]
+    host: Final[Optional[str]]
+    port: Final[Optional[int]]
+    raw_path: Final[str]
+    path: Final[str]
+    raw_query_string: Final[str]
+    query_string: Final[str]
+    path_qs: Final[str]
+    raw_path_qs: Final[str]
+    raw_fragment: Final[str]
+    fragment: Final[str]
+    query: Final[multidict.MultiDict[str]]
+    raw_name: Final[str]
+    name: Final[str]
+    raw_parts: Final[Tuple[str, ...]]
+    parts: Final[Tuple[str, ...]]
+    parent: Final[URL]
     def __init__(
         self, val: Union[str, "URL"] = ..., *, encoded: bool = ...
     ) -> None: ...
@@ -85,6 +85,7 @@ class URL:
     @classmethod
     def _normalize_path(cls, path: str) -> str: ...
 
+@final
 class cached_property:
     def __init__(self, wrapped: Any) -> None: ...
     def __get__(self, inst: URL, owner: Type[URL]) -> Any: ...