Drop wrong key parametrization for concrete classes (#682)

* Drop wrong key paramtrization for concrete classes

* Add changelog

* Rename

* Reformat changelog

CHANGES/682.bugfix

@@ -0,0 +1,10 @@
+Restored back ``MultiDict``, ``CIMultiDict``, ``MultiDictProxy``, and
+``CIMutiDictProxy`` generic type arguments; they are parametrized by value type, but the
+key type is fixed by container class.
+
+``MultiDict[int]`` means ``MutableMultiMapping[str, int]``. The key type of
+``MultiDict`` is always ``str``, while all str-like keys are accepted by API and
+converted to ``str`` internally.
+
+The same is true for ``CIMultiDict[int]`` which means ``MutableMultiMapping[istr,
+int]``. str-like keys are accepted but converted to ``istr`` internally.

multidict/__init__.pyi

@@ -63,9 +63,9 @@ class MutableMultiMapping(
     @abc.abstractmethod
     def popall(self, key: _S, default: _D) -> Union[List[_T], _D]: ...
 
-class MultiDict(MutableMultiMapping[_S, _T], Generic[_S, _T]):
+class MultiDict(MutableMultiMapping[str, _T]):
     def __init__(self, arg: _Arg[_S, _T] = ..., **kwargs: _T) -> None: ...
-    def copy(self) -> MultiDict[_S, _T]: ...
+    def copy(self) -> MultiDict[_T]: ...
     def __getitem__(self, k: _S) -> _T: ...
     def __setitem__(self, k: _S, v: _T) -> None: ...
     def __delitem__(self, v: _S) -> None: ...
@@ -90,9 +90,9 @@ class MultiDict(MutableMultiMapping[_S, _T], Generic[_S, _T]):
     @overload
     def popall(self, key: _S, default: _D) -> Union[List[_T], _D]: ...
 
-class CIMultiDict(MutableMultiMapping[_S, _T], Generic[_S, _T]):
+class CIMultiDict(MutableMultiMapping[istr, _T]):
     def __init__(self, arg: _Arg[_S, _T] = ..., **kwargs: _T) -> None: ...
-    def copy(self) -> CIMultiDict[_S, _T]: ...
+    def copy(self) -> CIMultiDict[_T]: ...
     def __getitem__(self, k: _S) -> _T: ...
     def __setitem__(self, k: _S, v: _T) -> None: ...
     def __delitem__(self, v: _S) -> None: ...
@@ -117,11 +117,11 @@ class CIMultiDict(MutableMultiMapping[_S, _T], Generic[_S, _T]):
     @overload
     def popall(self, key: _S, default: _D) -> Union[List[_T], _D]: ...
 
-class MultiDictProxy(MultiMapping[_S, _T], Generic[_S, _T]):
+class MultiDictProxy(MultiMapping[str, _T]):
     def __init__(
-        self, arg: Union[MultiMapping[_S, _T], MutableMultiMapping[_S, _T]]
+        self, arg: Union[MultiDict[_T], MultiDictProxy[_T]]
     ) -> None: ...
-    def copy(self) -> MultiDict[_S, _T]: ...
+    def copy(self) -> MultiDict[_T]: ...
     def __getitem__(self, k: _S) -> _T: ...
     def __iter__(self) -> Iterator[_S]: ...
     def __len__(self) -> int: ...
@@ -134,10 +134,11 @@ class MultiDictProxy(MultiMapping[_S, _T], Generic[_S, _T]):
     @overload
     def getone(self, key: _S, default: _D) -> Union[_T, _D]: ...
 
-class CIMultiDictProxy(MultiMapping[_S, _T], Generic[_S, _T]):
+class CIMultiDictProxy(MultiMapping[istr, _T]):
     def __init__(
-        self, arg: Union[MultiMapping[_S, _T], MutableMultiMapping[_S, _T]]
+        self, arg: Union[CIMultiDict[_T], CIMultiDictProxy[_T]]
     ) -> None: ...
+    def copy(self) -> CIMultiDict[_T]: ...
     def __getitem__(self, k: _S) -> _T: ...
     def __iter__(self) -> Iterator[_S]: ...
     def __len__(self) -> int: ...
@@ -149,13 +150,12 @@ class CIMultiDictProxy(MultiMapping[_S, _T], Generic[_S, _T]):
     def getone(self, key: _S) -> _T: ...
     @overload
     def getone(self, key: _S, default: _D) -> Union[_T, _D]: ...
-    def copy(self) -> CIMultiDict[_S, _T]: ...
 
 def getversion(
     md: Union[
-        MultiDict[_S, _T],
-        CIMultiDict[_S, _T],
-        MultiDictProxy[_S, _T],
-        CIMultiDictProxy[_S, _T],
+        MultiDict[_T],
+        CIMultiDict[_T],
+        MultiDictProxy[_T],
+        CIMultiDictProxy[_T],
     ]
 ) -> int: ...

tests/test_mypy.py

@@ -7,8 +7,8 @@
 
 
 def test_classes_not_abstract() -> None:
-    d1 = multidict.MultiDict({"a": "b"})  # type: multidict.MultiDict[str,str]
-    d2 = multidict.CIMultiDict({"a": "b"})  # type: multidict.CIMultiDict[str,str]
+    d1: multidict.MultiDict[str] = multidict.MultiDict({"a": "b"})
+    d2: multidict.CIMultiDict[str] = multidict.CIMultiDict({"a": "b"})
 
     d3 = multidict.MultiDictProxy(d1)
     d4 = multidict.CIMultiDictProxy(d2)