Make p into a property constructor

src/property_utils/properties/property.py

@@ -11,11 +11,6 @@
 except ImportError:
     from typing_extensions import Self  # Python <= 3.10
 
-try:
-    from typing import TypeAlias  # Python >= 3.10 pylint: disable=ungrouped-imports
-except ImportError:
-    from typing_extensions import TypeAlias  # Python < 3.10
-
 from property_utils.units.descriptors import (
     MeasurementUnit,
     Dimension,
@@ -25,6 +20,7 @@
 
 # pylint: disable=unused-wildcard-import, wildcard-import
 from property_utils.units.converters import *
+from property_utils.units.units import NonDimensionalUnit
 from property_utils.units.converter_types import UnitConverter, get_converter
 from property_utils.exceptions.units.converter_types import UndefinedConverterError
 from property_utils.exceptions.properties.property import (
@@ -37,6 +33,23 @@
 from property_utils.exceptions.base import PropertyUtilsException
 
 
+def p(
+    value: float, unit: UnitDescriptor = NonDimensionalUnit.NON_DIMENSIONAL
+) -> "Property":
+    """
+    Create a property with a value and a unit.
+    Default unit is non-dimensional, i.e. no unit.
+
+    >>> from property_utils.units import KELVIN
+    >>> p(350, KELVIN)
+    <Property: 350 K>
+
+    >>> p(20.23)
+    <Property: 20.23 >
+    """
+    return Property(value, unit)
+
+
 @dataclass
 class Property:
     """
@@ -573,6 +586,3 @@ def _validate_comparison_input(self, other) -> None:
                 f"cannot compare ({other}) to ({self}); "
                 f"({other}) must have ({self.unit.to_generic()}) units. "
             )
-
-
-p: TypeAlias = Property

src/property_utils/tests/properties/test_property.py

@@ -1,8 +1,9 @@
 from unittest import TestSuite, TextTestRunner
 
-from unittest_extensions import args
+from unittest_extensions import args, TestCase
 
-from property_utils.properties.property import Property
+from property_utils.properties.property import Property, p
+from property_utils.units.units import NonDimensionalUnit, PressureUnit
 from property_utils.exceptions.properties.property import (
     PropertyExponentError,
 )
@@ -62,6 +63,20 @@ def test_does_not_initialize_converter(self):
         self.assertIsNone(self.result().unit_converter)
 
 
+@add_to(property_test_suite)
+class TestPropertyConstructor(TestCase):
+    def subject(self, **kwargs):
+        return p(**kwargs)
+
+    @args({"value": 5})
+    def test_with_no_unit(self):
+        self.assertEqual(self.result().unit, NonDimensionalUnit.NON_DIMENSIONAL)
+
+    @args({"value": 5, "unit": PressureUnit.BAR})
+    def test_with_unit(self):
+        self.assertEqual(self.result().unit, PressureUnit.BAR)
+
+
 @add_to(property_test_suite, "eq")
 class TestPropertyEq(TestProperty):
 

src/property_utils/units/__init__.py

@@ -0,0 +1 @@
+from property_utils.units.aliases import *