Implements __int__ and __long__ for Quantity

Close #170

pint/compat/__init__.py

@@ -29,6 +29,8 @@ if PYTHON3:
         return x
 
     maketrans = str.maketrans
+
+    long_type = int
 else:
     from StringIO import StringIO
     string_types = basestring
@@ -41,6 +43,8 @@ else:
 
     maketrans = lambda f, t: dict((ord(a), b) for a, b in zip(f, t))
 
+    long_type = long
+
 if sys.version_info < (2, 7):
     try:
         import unittest2 as unittest

pint/quantity.py

@@ -16,7 +16,7 @@ import functools
 
 from .formatting import remove_custom_flags
 from .unit import DimensionalityError, UnitsContainer, UnitDefinition, UndefinedUnitError
-from .compat import string_types, ndarray, np, _to_magnitude
+from .compat import string_types, ndarray, np, _to_magnitude, long_type
 from .util import logger
 
 
@@ -276,6 +276,16 @@ class _Quantity(object):
         return self.__class__(magnitude, other)
 
     # Mathematical operations
+    def __int__(self):
+        if self.dimensionless:
+            return int(self._convert_magnitude_not_inplace(UnitsContainer()))
+        raise DimensionalityError(self.units, 'dimensionless')
+
+    def __long__(self):
+        if self.dimensionless:
+            return long_type(self._convert_magnitude_not_inplace(UnitsContainer()))
+        raise DimensionalityError(self.units, 'dimensionless')
+
     def __float__(self):
         if self.dimensionless:
             return float(self._convert_magnitude_not_inplace(UnitsContainer()))

pint/testsuite/helpers.py

@@ -2,7 +2,7 @@
 
 from __future__ import division, unicode_literals, print_function, absolute_import
 
-from pint.compat import unittest, HAS_NUMPY, HAS_UNCERTAINTIES, NUMPY_VER
+from pint.compat import unittest, HAS_NUMPY, HAS_UNCERTAINTIES, NUMPY_VER, PYTHON3
 
 
 def requires_numpy18():
@@ -24,3 +24,10 @@ def requires_uncertainties():
 def requires_not_uncertainties():
     return unittest.skipIf(HAS_UNCERTAINTIES, 'Requires Uncertainties is not installed.')
 
+
+def requires_python2():
+    return unittest.skipIf(PYTHON3, 'Requires Python 2.X.')
+
+
+def requires_python3():
+    return unittest.skipUnless(PYTHON3, 'Requires Python 3.X.')

pint/testsuite/test_issues.py

@@ -8,7 +8,7 @@ from pint import UnitRegistry
 from pint.unit import UnitsContainer
 from pint.util import ParserHelper
 
-from pint.compat import np, unittest
+from pint.compat import np, unittest, long_type
 from pint.testsuite import QuantityTestCase, helpers
 
 
@@ -250,6 +250,21 @@ class TestIssues(QuantityTestCase):
         self.assertQuantityAlmostEqual(summer(y), ureg.Quantity(3, 'meter'))
         self.assertQuantityAlmostEqual(y[0], ureg.Quantity(1, 'meter'))
 
+    def test_issue170(self):
+        Q_ = UnitRegistry().Quantity
+        q = Q_('1 kHz')/Q_('100 Hz')
+        iq = int(q)
+        self.assertEqual(iq, 10)
+        self.assertIsInstance(iq, int)
+
+    @helpers.requires_python2()
+    def test_issue170b(self):
+        Q_ = UnitRegistry().Quantity
+        q = Q_('1 kHz')/Q_('100 Hz')
+        iq = long(q)
+        self.assertEqual(iq, long(10))
+        self.assertIsInstance(iq, long)
+
 
 @helpers.requires_numpy()
 class TestIssuesNP(QuantityTestCase):