updating value manager to use deepcopy instead of copy

changelog

@@ -1,5 +1,8 @@
 CHANGELOG
 
+0.8.4
+* changing value manager previous value copying to deepcopy
+
 0.8.3
 * better logging for operational errors
 

cqlengine/VERSION

@@ -1 +1 @@
-0.8.3
+0.8.4

cqlengine/columns.py

@@ -1,5 +1,5 @@
 #column field types
-from copy import copy
+from copy import deepcopy
 from datetime import datetime
 from datetime import date
 import re
@@ -8,12 +8,13 @@ from cql.query import cql_quote
 
 from cqlengine.exceptions import ValidationError
 
+
 class BaseValueManager(object):
 
     def __init__(self, instance, column, value):
         self.instance = instance
         self.column = column
-        self.previous_value = copy(value)
+        self.previous_value = deepcopy(value)
         self.value = value
 
     @property
@@ -31,7 +32,7 @@ class BaseValueManager(object):
         return self.value != self.previous_value
 
     def reset_previous_value(self):
-        self.previous_value = copy(self.value)
+        self.previous_value = deepcopy(self.value)
 
     def getval(self):
         return self.value
@@ -52,6 +53,7 @@ class BaseValueManager(object):
         else:
             return property(_get, _set)
 
+
 class ValueQuoter(object):
     """
     contains a single value, which will quote itself for CQL insertion statements

cqlengine/tests/columns/test_container_columns.py

@@ -145,8 +145,6 @@ class TestSetColumn(BaseCassEngTestCase):
         column = columns.Set(columns.Text(min_length=100))
         assert isinstance(column.value_col, columns.Text)
 
-
-
     def test_to_python(self):
         """ Tests that to_python of value column is called """
         column = columns.Set(JsonTestColumn)