Update quantity repr

- Update CHANGES
- Add test for repr
- Update repr function to include magnitude repr & units

CHANGES

@@ -11,6 +11,8 @@ Pint Changelog
   (Issue #1030, #574)
 - Added angular frequency documentation page.
 - Move ASV benchmarks to dedicated folder. (Issue #1542)
+- Change Quantity repr to include magnitude repr & units.
+
 
 0.19.2 (2022-04-23)
 -------------------

pint/facets/plain/quantity.py

@@ -267,10 +267,7 @@ def __bytes__(self) -> bytes:
         return str(self).encode(locale.getpreferredencoding())
 
     def __repr__(self) -> str:
-        if isinstance(self._magnitude, float):
-            return f"<Quantity({self._magnitude:.9}, '{self._units}')>"
-        else:
-            return f"<Quantity({self._magnitude}, '{self._units}')>"
+        return f"<Quantity({self._magnitude!r}, units='{self._units}')>"
 
     def __hash__(self) -> int:
         self_base = self.to_base_units()

pint/testsuite/test_quantity.py

@@ -121,7 +121,18 @@ def test_quantity_comparison_convert(self):
     def test_quantity_repr(self):
         x = self.Q_(4.2, UnitsContainer(meter=1))
         assert str(x) == "4.2 meter"
-        assert repr(x) == "<Quantity(4.2, 'meter')>"
+        assert repr(x) == "<Quantity(4.2, units='meter')>"
+        x=self.Q_(2.9325156461464651456456545649)
+        assert repr(x) == "<Quantity(2.932515646146465, units='dimensionless')>"
+
+    @helpers.requires_numpy
+    def test_quantity_repr_numpy(self):
+        x = self.Q_(4.2)
+        assert repr(x) == "<Quantity(4.2, units='dimensionless')>"
+        x = self.Q_(np.array(2.))
+        assert repr(x) == "<Quantity(array(2.), units='dimensionless')>"
+        x = self.Q_(np.array(2., dtype=np.float32))
+        assert repr(x) == "<Quantity(array(2., dtype=float32), units='dimensionless')>"
 
     def test_quantity_hash(self):
         x = self.Q_(4.2, "meter")