its a bad idea to use mutable default parameter

Change-Id: I753b5d3c896b5d6622c63356b013d4f53edd4571

vitrage/datasources/rescheduler.py

@@ -57,7 +57,7 @@ class ReScheduler(object):
                  times=-1,
                  ttl=None,
                  fault_callback=None,
-                 fault_callback_kwargs={}):
+                 fault_callback_kwargs=None):
         """Schedule a new task
 
         :param func: function to run
@@ -86,6 +86,8 @@ class ReScheduler(object):
         :return: None
         """
 
+        if fault_callback_kwargs is None:
+            fault_callback_kwargs = {}
         if times == 0:
             return None
 
@@ -140,8 +142,10 @@ class ReScheduler(object):
                      times=-1,
                      ttl=None,
                      fault_callback=None,
-                     fault_callback_kwargs={}):
+                     fault_callback_kwargs=None):
 
+            if fault_callback_kwargs is None:
+                fault_callback_kwargs = {}
             self.scheduler = scheduler
             self.func = func
             self.args = args

vitrage/tests/unit/datasources/aodh/test_aodh_driver.py

@@ -184,9 +184,10 @@ class AodhDriverTest(base.BaseTest):
     def _extract_alarm_data(self,
                             state="ok",
                             type="event",
-                            rule={"query": [],
-                                  "event_type": "*"}):
+                            rule=None):
 
+        if rule is None:
+            rule = {"query": [], "event_type": "*"}
         return {AodhProps.DESCRIPTION: "test",
                 AodhProps.TIMESTAMP: "2016-11-09T01:39:13.839584",
                 AodhProps.ENABLED: True,