Merge pull request #460 from datastax/468

PYTHON-468 - Decimal serlz accepts primitive numeric types and tuple

cassandra/cqltypes.py

@@ -369,7 +369,7 @@ class DecimalType(_CassandraType):
         try:
             sign, digits, exponent = dec.as_tuple()
         except AttributeError:
-            raise TypeError("Non-Decimal type received for Decimal value")
+            sign, digits, exponent = Decimal(dec).as_tuple()
         unscaled = int(''.join([str(digit) for digit in digits]))
         if sign:
             unscaled *= -1

tests/unit/test_marshalling.py

@@ -11,7 +11,10 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+import sys
+
 from cassandra.marshal import bitlength
+from cassandra.protocol import MAX_SUPPORTED_VERSION
 
 try:
     import unittest2 as unittest
@@ -24,7 +27,7 @@ from decimal import Decimal
 from uuid import UUID
 
 from cassandra.cqltypes import lookup_casstype, DecimalType, UTF8Type, DateType
-from cassandra.util import OrderedMap, OrderedMapSerializedKey, sortedset, Time, Date
+from cassandra.util import OrderedMapSerializedKey, sortedset, Time, Date
 
 marshalled_value_pairs = (
     # binary form, type, python native type
@@ -139,3 +142,21 @@ class UnmarshalTest(unittest.TestCase):
     def test_date(self):
         # separate test because it will deserialize as datetime
         self.assertEqual(DateType.from_binary(DateType.to_binary(date(2015, 11, 2), 1), 1), datetime(2015, 11, 2))
+
+    def test_decimal(self):
+        # testing implicit numeric conversion
+        # int, tuple(sign, digits, exp), float
+        converted_types = (10001, (0, (1, 0, 0, 0, 0, 1), -3), 100.1)
+
+        if sys.version_info < (2, 7):
+            # Decimal in Python 2.6 does not accept floats for lossless initialization
+            # Just verifying expected exception here
+            f = converted_types[-1]
+            self.assertIsInstance(f, float)
+            self.assertRaises(TypeError, DecimalType.to_binary, f, MAX_SUPPORTED_VERSION)
+            converted_types = converted_types[:-1]
+
+        for proto_ver in range(1, MAX_SUPPORTED_VERSION + 1):
+            for n in converted_types:
+                expected = Decimal(n)
+                self.assertEqual(DecimalType.from_binary(DecimalType.to_binary(n, proto_ver), proto_ver), expected)