Allow pint.registry.Quantity to be used as a generic class (#2231)

* Generic quantity

* Added note to CHANGES

* Added parameterized Quantity type to UnitRegistry class definition.

* Fixed linting issues

---------

Co-authored-by: ZacharySchaller <[email protected]>

Author: zschaller27

CHANGES

@@ -8,7 +8,7 @@ Pint Changelog
 - Add devcontainer.json to add GitHub Codespace support (#2208)
 - Add support for `numpy.geomspace` (#2206)
 - Add support for `linalg.diagonal`, `linalg.matrix_transpose`, `diag`, `tril`, `triu`, `linalg.eigvals`, `linalg.eigvalsh`, `linalg.matrix_norm` and `linalg.vector_norm` (#2210)
-
+- Add support for `pint.Quantity` being used as Generic.
 
 0.25.0 (2025-08-25)
 -------------------

pint/facets/context/registry.py

@@ -427,7 +427,7 @@ def _get_compatible_units(
 
 
 class ContextRegistry(
-    GenericContextRegistry[objects.ContextQuantity[Any], objects.ContextUnit]
+    GenericContextRegistry[objects.ContextQuantity, objects.ContextUnit]
 ):
-    Quantity: TypeAlias = objects.ContextQuantity[Any]
+    Quantity: TypeAlias = objects.ContextQuantity
     Unit: TypeAlias = objects.ContextUnit

pint/facets/dask/__init__.py

@@ -11,7 +11,7 @@
 from __future__ import annotations
 
 import functools
-from typing import Any, Generic
+from typing import Generic
 
 from ...compat import TypeAlias, compute, dask_array, persist, visualize
 from ..plain import (
@@ -136,6 +136,6 @@ class GenericDaskRegistry(
     pass
 
 
-class DaskRegistry(GenericDaskRegistry[DaskQuantity[Any], DaskUnit]):
-    Quantity: TypeAlias = DaskQuantity[Any]
+class DaskRegistry(GenericDaskRegistry[DaskQuantity, DaskUnit]):
+    Quantity: TypeAlias = DaskQuantity
     Unit: TypeAlias = DaskUnit

pint/facets/measurement/registry.py

@@ -8,7 +8,7 @@
 
 from __future__ import annotations
 
-from typing import Any, Generic
+from typing import Generic
 
 from ...compat import TypeAlias, ufloat
 from ...util import create_class_with_registry
@@ -38,9 +38,7 @@ def no_uncertainties(*args, **kwargs):
 
 
 class MeasurementRegistry(
-    GenericMeasurementRegistry[
-        objects.MeasurementQuantity[Any], objects.MeasurementUnit
-    ]
+    GenericMeasurementRegistry[objects.MeasurementQuantity, objects.MeasurementUnit]
 ):
-    Quantity: TypeAlias = objects.MeasurementQuantity[Any]
+    Quantity: TypeAlias = objects.MeasurementQuantity
     Unit: TypeAlias = objects.MeasurementUnit

pint/facets/nonmultiplicative/registry.py

@@ -302,8 +302,8 @@ def _convert(
 
 class NonMultiplicativeRegistry(
     GenericNonMultiplicativeRegistry[
-        objects.NonMultiplicativeQuantity[Any], objects.NonMultiplicativeUnit
+        objects.NonMultiplicativeQuantity, objects.NonMultiplicativeUnit
     ]
 ):
-    Quantity: TypeAlias = objects.NonMultiplicativeQuantity[Any]
+    Quantity: TypeAlias = objects.NonMultiplicativeQuantity
     Unit: TypeAlias = objects.NonMultiplicativeUnit

pint/facets/numpy/registry.py

@@ -8,7 +8,7 @@
 
 from __future__ import annotations
 
-from typing import Any, Generic
+from typing import Generic
 
 from ...compat import TypeAlias
 from ..plain import GenericPlainRegistry, QuantityT, UnitT
@@ -22,6 +22,6 @@ class GenericNumpyRegistry(
     pass
 
 
-class NumpyRegistry(GenericPlainRegistry[NumpyQuantity[Any], NumpyUnit]):
-    Quantity: TypeAlias = NumpyQuantity[Any]
+class NumpyRegistry(GenericPlainRegistry[NumpyQuantity, NumpyUnit]):
+    Quantity: TypeAlias = NumpyQuantity
     Unit: TypeAlias = NumpyUnit

pint/facets/plain/registry.py

@@ -160,7 +160,7 @@ def __call__(self, *args: Any, **kwargs: Any):
 
 
 # Generic types used to mark types associated to Registries.
-QuantityT = TypeVar("QuantityT", bound=PlainQuantity[Any])
+QuantityT = TypeVar("QuantityT", bound=PlainQuantity)
 UnitT = TypeVar("UnitT", bound=PlainUnit)
 
 
@@ -1476,6 +1476,6 @@ def UnitsContainer(self, *args: Any, **kwargs: Any) -> UnitsContainer:
     __call__ = parse_expression
 
 
-class PlainRegistry(GenericPlainRegistry[PlainQuantity[Any], PlainUnit]):
-    Quantity: TypeAlias = PlainQuantity[Any]
+class PlainRegistry(GenericPlainRegistry[PlainQuantity, PlainUnit]):
+    Quantity: TypeAlias = PlainQuantity
     Unit: TypeAlias = PlainUnit

pint/facets/system/registry.py

@@ -9,7 +9,7 @@
 from __future__ import annotations
 
 from numbers import Number
-from typing import TYPE_CHECKING, Any, Generic
+from typing import TYPE_CHECKING, Generic
 
 from ... import errors
 from ...compat import TypeAlias
@@ -258,8 +258,6 @@ def _get_compatible_units(
             raise ex
 
 
-class SystemRegistry(
-    GenericSystemRegistry[objects.SystemQuantity[Any], objects.SystemUnit]
-):
-    Quantity: TypeAlias = objects.SystemQuantity[Any]
+class SystemRegistry(GenericSystemRegistry[objects.SystemQuantity, objects.SystemUnit]):
+    Quantity: TypeAlias = objects.SystemQuantity
     Unit: TypeAlias = objects.SystemUnit

pint/registry.py

@@ -26,13 +26,14 @@
 
 
 class Quantity(
-    facets.SystemRegistry.Quantity,
-    facets.ContextRegistry.Quantity,
-    facets.DaskRegistry.Quantity,
-    facets.NumpyRegistry.Quantity,
-    facets.MeasurementRegistry.Quantity,
-    facets.NonMultiplicativeRegistry.Quantity,
-    facets.PlainRegistry.Quantity,
+    Generic[facets.MagnitudeT],
+    facets.SystemRegistry.Quantity[facets.MagnitudeT],
+    facets.ContextRegistry.Quantity[facets.MagnitudeT],
+    facets.DaskRegistry.Quantity[facets.MagnitudeT],
+    facets.NumpyRegistry.Quantity[facets.MagnitudeT],
+    facets.MeasurementRegistry.Quantity[facets.MagnitudeT],
+    facets.NonMultiplicativeRegistry.Quantity[facets.MagnitudeT],
+    facets.PlainRegistry.Quantity[facets.MagnitudeT],
 ):
     pass
 
@@ -62,7 +63,7 @@ class GenericUnitRegistry(
     pass
 
 
-class UnitRegistry(GenericUnitRegistry[Quantity, Unit]):
+class UnitRegistry(GenericUnitRegistry[Quantity[facets.MagnitudeT], Unit]):
     """The unit registry stores the definitions and relationships between units.
 
     Parameters

pint/testsuite/test_quantity.py

@@ -2062,3 +2062,10 @@ def test_types(self):
         assert isinstance(quantity.m, float)
 
         assert isinstance(self.ureg.m, self.ureg.Unit)
+
+
+class TestGenericQuantityTyping:
+    def test_generic_type_use(self):
+        from pint import Quantity
+
+        _ = Quantity[int]