[SPARK-7978] [SQL] [PYSPARK] DecimalType should not be singleton

Author: Davies Liu <davies@databricks.com>

Closes #6532 from davies/decimal and squashes the following commits:

c7fcbce [Davies Liu] Update tests.py
1425359 [Davies Liu] DecimalType should not be singleton

2 files changed, 25 insertions, 2 deletions

diff --git a/python/pyspark/sql/tests.py b/python/pyspark/sql/tests.py
index 5c53c3a8ed..76384d31f1 100644
--- a/python/pyspark/sql/tests.py
+++ b/python/pyspark/sql/tests.py
@@ -100,6 +100,15 @@ class DataTypeTests(unittest.TestCase):
         lt2 = pickle.loads(pickle.dumps(LongType()))
         self.assertEquals(lt, lt2)
 
+    # regression test for SPARK-7978
+    def test_decimal_type(self):
+        t1 = DecimalType()
+        t2 = DecimalType(10, 2)
+        self.assertTrue(t2 is not t1)
+        self.assertNotEqual(t1, t2)
+        t3 = DecimalType(8)
+        self.assertNotEqual(t2, t3)
+
 
 class SQLTests(ReusedPySparkTestCase):
 
diff --git a/python/pyspark/sql/types.py b/python/pyspark/sql/types.py
index 9e7e9f04bc..b6ec6137c9 100644
--- a/python/pyspark/sql/types.py
+++ b/python/pyspark/sql/types.py
@@ -97,8 +97,6 @@ class AtomicType(DataType):
     """An internal type used to represent everything that is not
     null, UDTs, arrays, structs, and maps."""
 
-    __metaclass__ = DataTypeSingleton
-
 
 class NumericType(AtomicType):
     """Numeric data types.
@@ -109,6 +107,8 @@ class IntegralType(NumericType):
     """Integral data types.
     """
 
+    __metaclass__ = DataTypeSingleton
+
 
 class FractionalType(NumericType):
     """Fractional data types.
@@ -119,26 +119,36 @@ class StringType(AtomicType):
     """String data type.
     """
 
+    __metaclass__ = DataTypeSingleton
+
 
 class BinaryType(AtomicType):
     """Binary (byte array) data type.
     """
 
+    __metaclass__ = DataTypeSingleton
+
 
 class BooleanType(AtomicType):
     """Boolean data type.
     """
 
+    __metaclass__ = DataTypeSingleton
+
 
 class DateType(AtomicType):
     """Date (datetime.date) data type.
     """
 
+    __metaclass__ = DataTypeSingleton
+
 
 class TimestampType(AtomicType):
     """Timestamp (datetime.datetime) data type.
     """
 
+    __metaclass__ = DataTypeSingleton
+
 
 class DecimalType(FractionalType):
     """Decimal (decimal.Decimal) data type.
@@ -172,11 +182,15 @@ class DoubleType(FractionalType):
     """Double data type, representing double precision floats.
     """
 
+    __metaclass__ = DataTypeSingleton
+
 
 class FloatType(FractionalType):
     """Float data type, representing single precision floats.
     """
 
+    __metaclass__ = DataTypeSingleton
+
 
 class ByteType(IntegralType):
     """Byte data type, i.e. a signed integer in a single byte.