TypeConversionDict.get type can be a callable

pallets · Nov 4, 2024 · acdf7fa · acdf7fa
1 parent f27e476
commit acdf7fa
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Showing 3 changed files with 44 additions and 23 deletions.
diff --git a/CHANGES.rst b/CHANGES.rst
@@ -5,6 +5,10 @@ Version 3.1.2
 
 Unreleased
 
+-   Improve type annotation for ``TypeConversionDict.get`` to allow the ``type``
+    parameter to be a callable. :issue:`2988`
+
+
 
 Version 3.1.1
 -------------

diff --git a/src/werkzeug/datastructures/headers.py b/src/werkzeug/datastructures/headers.py
@@ -114,11 +114,14 @@ def get(self, key: str, default: str) -> str: ...
     @t.overload
     def get(self, key: str, default: T) -> str | T: ...
     @t.overload
-    def get(self, key: str, type: type[T]) -> T | None: ...
+    def get(self, key: str, type: cabc.Callable[[str], T]) -> T | None: ...
     @t.overload
-    def get(self, key: str, default: T, type: type[T]) -> T: ...
+    def get(self, key: str, default: T, type: cabc.Callable[[str], T]) -> T: ...
     def get(  # type: ignore[misc]
-        self, key: str, default: str | T | None = None, type: type[T] | None = None
+        self,
+        key: str,
+        default: str | T | None = None,
+        type: cabc.Callable[[str], T] | None = None,
     ) -> str | T | None:
         """Return the default value if the requested data doesn't exist.
         If `type` is provided and is a callable it should convert the value,
@@ -153,15 +156,17 @@ def get(  # type: ignore[misc]
             return rv
 
         try:
-            return type(rv)  # type: ignore[call-arg]
+            return type(rv)
         except ValueError:
             return default
 
     @t.overload
     def getlist(self, key: str) -> list[str]: ...
     @t.overload
-    def getlist(self, key: str, type: type[T]) -> list[T]: ...
-    def getlist(self, key: str, type: type[T] | None = None) -> list[str] | list[T]:
+    def getlist(self, key: str, type: cabc.Callable[[str], T]) -> list[T]: ...
+    def getlist(
+        self, key: str, type: cabc.Callable[[str], T] | None = None
+    ) -> list[str] | list[T]:
         """Return the list of items for a given key. If that key is not in the
         :class:`Headers`, the return value will be an empty list.  Just like
         :meth:`get`, :meth:`getlist` accepts a `type` parameter.  All items will
@@ -187,7 +192,7 @@ def getlist(self, key: str, type: type[T] | None = None) -> list[str] | list[T]:
             for k, v in self:
                 if k.lower() == ikey:
                     try:
-                        result.append(type(v))  # type: ignore[call-arg]
+                        result.append(type(v))
                     except ValueError:
                         continue
 

diff --git a/src/werkzeug/datastructures/structures.py b/src/werkzeug/datastructures/structures.py
@@ -69,11 +69,14 @@ def get(self, key: K, default: V) -> V: ...
     @t.overload
     def get(self, key: K, default: T) -> V | T: ...
     @t.overload
-    def get(self, key: str, type: type[T]) -> T | None: ...
+    def get(self, key: str, type: cabc.Callable[[V], T]) -> T | None: ...
     @t.overload
-    def get(self, key: str, default: T, type: type[T]) -> T: ...
+    def get(self, key: str, default: T, type: cabc.Callable[[V], T]) -> T: ...
     def get(  # type: ignore[misc]
-        self, key: K, default: V | T | None = None, type: type[T] | None = None
+        self,
+        key: K,
+        default: V | T | None = None,
+        type: cabc.Callable[[V], T] | None = None,
     ) -> V | T | None:
         """Return the default value if the requested data doesn't exist.
         If `type` is provided and is a callable it should convert the value,
@@ -108,7 +111,7 @@ def get(  # type: ignore[misc]
             return rv
 
         try:
-            return type(rv)  # type: ignore[call-arg]
+            return type(rv)
         except (ValueError, TypeError):
             return default
 
@@ -255,8 +258,10 @@ def add(self, key: K, value: V) -> None:
     @t.overload
     def getlist(self, key: K) -> list[V]: ...
     @t.overload
-    def getlist(self, key: K, type: type[T]) -> list[T]: ...
-    def getlist(self, key: K, type: type[T] | None = None) -> list[V] | list[T]:
+    def getlist(self, key: K, type: cabc.Callable[[V], T]) -> list[T]: ...
+    def getlist(
+        self, key: K, type: cabc.Callable[[V], T] | None = None
+    ) -> list[V] | list[T]:
         """Return the list of items for a given key. If that key is not in the
         `MultiDict`, the return value will be an empty list.  Just like `get`,
         `getlist` accepts a `type` parameter.  All items will be converted
@@ -279,7 +284,7 @@ def getlist(self, key: K, type: type[T] | None = None) -> list[V] | list[T]:
         result = []
         for item in rv:
             try:
-                result.append(type(item))  # type: ignore[call-arg]
+                result.append(type(item))
             except (ValueError, TypeError):
                 pass
         return result
@@ -707,8 +712,10 @@ def add(self, key: K, value: V) -> None:
     @t.overload
     def getlist(self, key: K) -> list[V]: ...
     @t.overload
-    def getlist(self, key: K, type: type[T]) -> list[T]: ...
-    def getlist(self, key: K, type: type[T] | None = None) -> list[V] | list[T]:
+    def getlist(self, key: K, type: cabc.Callable[[V], T]) -> list[T]: ...
+    def getlist(
+        self, key: K, type: cabc.Callable[[V], T] | None = None
+    ) -> list[V] | list[T]:
         rv: list[_omd_bucket[K, V]]
 
         try:
@@ -720,7 +727,7 @@ def getlist(self, key: K, type: type[T] | None = None) -> list[V] | list[T]:
         result = []
         for item in rv:
             try:
-                result.append(type(item.value))  # type: ignore[call-arg]
+                result.append(type(item.value))
             except (ValueError, TypeError):
                 pass
         return result
@@ -852,17 +859,20 @@ def get(self, key: K, default: V) -> V: ...
     @t.overload
     def get(self, key: K, default: T) -> V | T: ...
     @t.overload
-    def get(self, key: str, type: type[T]) -> T | None: ...
+    def get(self, key: str, type: cabc.Callable[[V], T]) -> T | None: ...
     @t.overload
-    def get(self, key: str, default: T, type: type[T]) -> T: ...
+    def get(self, key: str, default: T, type: cabc.Callable[[V], T]) -> T: ...
     def get(  # type: ignore[misc]
-        self, key: K, default: V | T | None = None, type: type[T] | None = None
+        self,
+        key: K,
+        default: V | T | None = None,
+        type: cabc.Callable[[V], T] | None = None,
     ) -> V | T | None:
         for d in self.dicts:
             if key in d:
                 if type is not None:
                     try:
-                        return type(d[key])  # type: ignore[call-arg]
+                        return type(d[key])
                     except (ValueError, TypeError):
                         continue
                 return d[key]
@@ -871,8 +881,10 @@ def get(  # type: ignore[misc]
     @t.overload
     def getlist(self, key: K) -> list[V]: ...
     @t.overload
-    def getlist(self, key: K, type: type[T]) -> list[T]: ...
-    def getlist(self, key: K, type: type[T] | None = None) -> list[V] | list[T]:
+    def getlist(self, key: K, type: cabc.Callable[[V], T]) -> list[T]: ...
+    def getlist(
+        self, key: K, type: cabc.Callable[[V], T] | None = None
+    ) -> list[V] | list[T]:
         rv = []
         for d in self.dicts:
             rv.extend(d.getlist(key, type))  # type: ignore[arg-type]