Remove arguments "{}" and "[]" in function definitions

remove mutable default arguments "{}" and "[]" in function definitions
refer to:http://docs.python-guide.org/en/latest/writing/gotchas/

Change-Id: Ib03d9820a259b2cbd83aa8bd675ac6153cf78ebd
Closes-Bug: #1527080

murano/common/policy.py

@@ -62,7 +62,10 @@ def init(default_rule=None, use_conf=True):
     _ENFORCER.load_rules()
 
 
-def check(rule, ctxt, target={}, do_raise=True, exc=exceptions.HTTPForbidden):
+def check(rule, ctxt, target=None, do_raise=True,
+          exc=exceptions.HTTPForbidden):
+    if target is None:
+        target = {}
     creds = ctxt.to_dict()
 
     try:

murano/dsl/exceptions.py

@@ -44,7 +44,9 @@ class NoMethodFound(Exception):
 
 
 class NoClassFound(Exception):
-    def __init__(self, name, packages=[]):
+    def __init__(self, name, packages=None):
+        if packages is None:
+            packages = []
         packages = ', '.join("{0}/{1}".format(p.name, p.version)
                              for p in packages)
         super(NoClassFound, self).__init__(

murano/services/actions.py

@@ -67,7 +67,9 @@ class ActionServices(object):
         return task_id
 
     @staticmethod
-    def execute(action_id, session, unit, token, args={}):
+    def execute(action_id, session, unit, token, args=None):
+        if args is None:
+            args = {}
         environment = actions_db.get_environment(session, unit)
         action = ActionServices.find_action(session.description, action_id)
         if action is None:

murano/tests/unit/api/base.py

@@ -89,11 +89,13 @@ class MuranoApiTestCase(base.MuranoWithDBTestCase, FakeLogMixin):
         super(MuranoApiTestCase, self).tearDown()
         timeutils.utcnow.override_time = None
 
-    def _stub_uuid(self, values=[]):
+    def _stub_uuid(self, values=None):
         class FakeUUID(object):
             def __init__(self, v):
                 self.hex = v
 
+        if values is None:
+            values = []
         mock_uuid4 = mock.patch('uuid.uuid4').start()
         mock_uuid4.side_effect = [FakeUUID(v) for v in values]
         return mock_uuid4
@@ -128,7 +130,9 @@ class ControllerTest(object):
         self._policy_check_expectations = []
         self._actual_policy_checks = []
 
-        def wrap_policy_check(rule, ctxt, target={}, **kwargs):
+        def wrap_policy_check(rule, ctxt, target=None, **kwargs):
+            if target is None:
+                target = {}
             self._actual_policy_checks.append((rule, target))
             return real_policy_check(rule, ctxt, target=target, **kwargs)
 
@@ -184,13 +188,16 @@ class ControllerTest(object):
 
     def _delete(self, path, params=None, user=DEFAULT_USER,
                 tenant=DEFAULT_TENANT):
-        params = params or {}
+        if params is None:
+            params = {}
         return self._simple_request(path, params=params, method='DELETE',
                                     user=user, tenant=tenant)
 
     def _data_request(self, path, data, content_type='application/json',
-                      method='POST', params={},
+                      method='POST', params=None,
                       user=DEFAULT_USER, tenant=DEFAULT_TENANT):
+        if params is None:
+            params = {}
         environ = self._environ(path)
         environ['REQUEST_METHOD'] = method
 
@@ -207,20 +214,26 @@ class ControllerTest(object):
 
         return req
 
-    def _post(self, path, data, content_type='application/json', params={},
+    def _post(self, path, data, content_type='application/json', params=None,
               user=DEFAULT_USER, tenant=DEFAULT_TENANT):
+        if params is None:
+            params = {}
         return self._data_request(path, data, content_type, params=params,
                                   user=user, tenant=tenant)
 
-    def _put(self, path, data, content_type='application/json', params={},
+    def _put(self, path, data, content_type='application/json', params=None,
              user=DEFAULT_USER, tenant=DEFAULT_TENANT):
+        if params is None:
+            params = {}
         return self._data_request(path, data, content_type, method='PUT',
                                   params=params, user=user, tenant=tenant)
 
     def _set_policy_rules(self, rules):
         policy.set_rules(rules, default_rule='default')
 
-    def expect_policy_check(self, action, target={}):
+    def expect_policy_check(self, action, target=None):
+        if target is None:
+            target = {}
         self._policy_check_expectations.append((action, target))
 
     def _assert_policy_checks(self):

murano/tests/unit/db/services/test_templates_service.py

@@ -85,11 +85,13 @@ class TestTemplateServices(base.MuranoWithDBTestCase,
         self.test_create_template()
         self.template_services.delete("template_id")
 
-    def _stub_uuid(self, values=[]):
+    def _stub_uuid(self, values=None):
         class FakeUUID(object):
             def __init__(self, v):
                 self.hex = v
 
+        if values is None:
+            values = []
         mock_uuid4 = mock.patch('uuid.uuid4').start()
         mock_uuid4.side_effect = [FakeUUID(v) for v in values]
         return mock_uuid4

murano/tests/unit/engine/system/test_agent.py

@@ -300,11 +300,13 @@ class TestExecutionPlan(base.MuranoTestCase):
             'Version': '1.0.0'
         }
 
-    def _stub_uuid(self, values=[]):
+    def _stub_uuid(self, values=None):
         class FakeUUID(object):
             def __init__(self, v):
                 self.hex = v
 
+        if values is None:
+            values = []
         mock_uuid4 = mock.patch('uuid.uuid4').start()
         mock_uuid4.side_effect = [FakeUUID(v) for v in values]
         return mock_uuid4

murano/tests/unit/utils.py

@@ -18,8 +18,10 @@ from murano.db import session
 
 
 def dummy_context(user='test_username', tenant_id='test_tenant_id',
-                  password='password', roles=[], user_id=None,
+                  password='password', roles=None, user_id=None,
                   is_admin=False, request_id='dummy-request'):
+    if roles is None:
+        roles = []
     # NOTE(kzaitsev) passing non-False value by default to request_id, to
     # prevent generation during tests.
     return context.RequestContext.from_dict({