Merge branch 'master' into develop

.gitignore

@@ -12,3 +12,6 @@ MANIFEST
 
 # WebDAV file system cache files
 .DAV/
+
+# tags files (from ctags)
+tags

pint/default_en.txt

@@ -72,6 +72,10 @@ cmil = 5.067075e-10 * m ** 2 = circular_mils
 darcy = 9.869233e-13 * m ** 2
 hectare = 100 * are = ha
 
+# Concentration
+[concentration] = [substance] / [volume]
+molar = mol / (1e-3 * m ** 3) = M
+
 # EM
 esu = 1 * erg**0.5 * centimeter**0.5 = statcoulombs = statC = franklin = Fr
 esu_per_second = 1 * esu / second = statampere

pint/quantity.py

@@ -142,6 +142,13 @@ class _Quantity(SharedRegistryObject):
     def __repr__(self):
         return "<Quantity({0}, '{1}')>".format(self._magnitude, self._units)
 
+    def __hash__(self):
+        self_base = self.to_base_units()
+        if self_base.dimensionless:
+            return hash(self_base.magnitude)
+        else:
+            return hash((self_base.__class__, self_base.magnitude, self_base.units))
+
     def __format__(self, spec):
         spec = spec or self.default_format
 
@@ -393,7 +400,7 @@ class _Quantity(SharedRegistryObject):
             warnings.warn(w, stacklevel=2)
             return self
 
-        if (self.unitless or self.magnitude==0 or 
+        if (self.unitless or self.magnitude==0 or
             math.isnan(self.magnitude) or math.isinf(self.magnitude)):
             return self
 

pint/testsuite/test_issues.py

@@ -39,7 +39,6 @@ class TestIssues(QuantityTestCase):
 
     def test_issue29(self):
         ureg = UnitRegistry()
-        ureg.define('molar = mole / liter = M')
         t = 4 * ureg('mM')
         self.assertEqual(t.magnitude, 4)
         self.assertEqual(t._units, UnitsContainer(millimolar=1))

pint/testsuite/test_quantity.py

@@ -90,6 +90,22 @@ class TestQuantity(QuantityTestCase):
         self.assertEqual(str(x), '4.2 meter')
         self.assertEqual(repr(x), "<Quantity(4.2, 'meter')>")
 
+    def test_quantity_hash(self):
+        x = self.Q_(4.2, 'meter')
+        x2 = self.Q_(4200, 'millimeter')
+        y = self.Q_(2, 'second')
+        z = self.Q_(0.5, 'hertz')
+        self.assertEqual(hash(x), hash(x2))
+
+        # Dimensionless equality
+        self.assertEqual(hash(y * z), hash(1.0))
+
+        # Dimensionless equality from a different unit registry
+        ureg2 = UnitRegistry(force_ndarray=self.FORCE_NDARRAY)
+        y2 = ureg2.Quantity(2, 'second')
+        z2 = ureg2.Quantity(0.5, 'hertz')
+        self.assertEqual(hash(y * z), hash(y2 * z2))
+
     def test_quantity_format(self):
         x = self.Q_(4.12345678, UnitsContainer(meter=2, kilogram=1, second=-1))
         for spec, result in (('{0}', str(x)), ('{0!s}', str(x)), ('{0!r}', repr(x)),