Merge #501

501: Fixes for issues #95, #468, #483, #462 r=hgrecco

pint/quantity.py

@@ -893,9 +893,21 @@ class _Quantity(SharedRegistryObject):
 
             if isinstance(getattr(other, '_magnitude', other), ndarray):
                 # arrays are refused as exponent, because they would create
-                #  len(array) quanitites of len(set(array)) different units
-                if np.size(other) > 1:
-                    raise DimensionalityError(self._units, 'dimensionless')
+                # len(array) quantities of len(set(array)) different units
+                # unless the base is dimensionless.
+                if self.dimensionless:
+                    if getattr(other, 'dimensionless', False):
+                        self._magnitude **= other.m_as('')
+                        return self
+                    elif not getattr(other, 'dimensionless', True):
+                        raise DimensionalityError(other._units, 'dimensionless')
+                    else:
+                        self._magnitude **= other
+                        return self
+                elif np.size(other) > 1:
+                    raise DimensionalityError(self._units, 'dimensionless',
+                                              extra_msg='Quantity array exponents are only allowed '
+                                                        'if the base is dimensionless')
 
             if other == 1:
                 return self
@@ -930,9 +942,19 @@ class _Quantity(SharedRegistryObject):
 
             if isinstance(getattr(other, '_magnitude', other), ndarray):
                 # arrays are refused as exponent, because they would create
-                #  len(array) quantities of len(set(array)) different units
-                if np.size(other) > 1:
-                    raise DimensionalityError(self._units, 'dimensionless')
+                # len(array) quantities of len(set(array)) different units
+                # unless the base is dimensionless.
+                if self.dimensionless:
+                    if getattr(other, 'dimensionless', False):
+                        return self.__class__(self.m ** other.m_as(''))
+                    elif not getattr(other, 'dimensionless', True):
+                        raise DimensionalityError(other._units, 'dimensionless')
+                    else:
+                        return self.__class__(self.m ** other)
+                elif np.size(other) > 1:
+                    raise DimensionalityError(self._units, 'dimensionless',
+                                              extra_msg='Quantity array exponents are only allowed '
+                                                        'if the base is dimensionless')
 
             new_self = self
             if other == 1:
@@ -1052,6 +1074,7 @@ class _Quantity(SharedRegistryObject):
     #: will set on output.
     __set_units = {'cos': '', 'sin': '', 'tan': '',
                    'cosh': '', 'sinh': '', 'tanh': '',
+                   'log': '', 'exp': '',
                    'arccos': __radian, 'arcsin': __radian,
                    'arctan': __radian, 'arctan2': __radian,
                    'arccosh': __radian, 'arcsinh': __radian,

pint/registry.py

@@ -225,9 +225,10 @@ class BaseRegistry(meta.with_metaclass(_Meta)):
         """
 
         if isinstance(definition, string_types):
-            definition = Definition.from_string(definition)
-
-        self._define(definition)
+            for line in definition.split('\n'):
+                self._define(Definition.from_string(line))
+        else:
+            self._define(definition)
 
     def _define(self, definition):
         """Add unit to the registry.

pint/registry_helpers.py

@@ -29,7 +29,7 @@ def _replace_units(original_units, values_by_name):
     return getattr(q, "_units", UnitsContainer({}))
 
 
-def _to_units_container(a):
+def _to_units_container(a, registry=None):
     """Convert a unit compatible type to a UnitsContainer,
     checking if it is string field prefixed with an equal
     (which is considered a reference)
@@ -38,10 +38,10 @@ def _to_units_container(a):
     """
     if isinstance(a, string_types) and '=' in a:
         return to_units_container(a.split('=', 1)[1]), True
-    return to_units_container(a), False
+    return to_units_container(a, registry), False
 
 
-def _parse_wrap_args(args):
+def _parse_wrap_args(args, registry=None):
 
     # Arguments which contain definitions
     # (i.e. names that appear alone and for the first time)
@@ -55,7 +55,7 @@ def _parse_wrap_args(args):
     unit_args_ndx = set()
 
     # _to_units_container
-    args_as_uc = [_to_units_container(arg) for arg in args]
+    args_as_uc = [_to_units_container(arg, registry) for arg in args]
 
     # Check for references in args, remove None values
     for ndx, (arg, is_ref) in enumerate(args_as_uc):
@@ -154,9 +154,9 @@ def wraps(ureg, ret, args, strict=True):
     converter = _parse_wrap_args(args)
 
     if isinstance(ret, (list, tuple)):
-        container, ret = True, ret.__class__([_to_units_container(arg) for arg in ret])
+        container, ret = True, ret.__class__([_to_units_container(arg, ureg) for arg in ret])
     else:
-        container, ret = False, _to_units_container(ret)
+        container, ret = False, _to_units_container(ret, ureg)
 
     def decorator(func):
         assigned = tuple(attr for attr in functools.WRAPPER_ASSIGNMENTS if hasattr(func, attr))

pint/testsuite/test_issues.py

@@ -530,3 +530,27 @@ class TestIssuesNP(QuantityTestCase):
                          '1 count')
         self.assertEqual('{0:~}'.format(1 * self.ureg('MiB')),
                          '1 MiB')
+
+    def test_issue482(self):
+        q = self.ureg.Quantity(1, self.ureg.dimensionless)
+        qe = np.exp(q)
+        self.assertIsInstance(qe, self.ureg.Quantity)
+
+    def test_issue468(self):
+        ureg = UnitRegistry()
+
+        @ureg.wraps(('kg'), 'meter')
+        def f(x):
+            return x
+
+        x = ureg.Quantity(1., 'meter')
+        y = f(x)
+        z = x * y
+        self.assertEquals(z, ureg.Quantity(1., 'meter * kilogram'))
+
+    def test_issue483(self):
+        ureg = self.ureg
+        a = np.asarray([1, 2, 3])
+        q = [1, 2, 3] * ureg.dimensionless
+        p = (q ** q).m
+        np.testing.assert_array_equal(p, a ** a)

pint/testsuite/test_numpy.py

@@ -427,7 +427,7 @@ class TestNDArrayQunatityMath(QuantityTestCase):
     @helpers.requires_numpy()
     def test_exponentiation_array_exp(self):
         arr = np.array(range(3), dtype=np.float)
-        q = self.Q_(arr, None)
+        q = self.Q_(arr, 'meter')
 
         for op_ in [op.pow, op.ipow]:
             q_cp = copy.copy(q)