Python3 common patterns

Modify some codes in order to make them meet
the Python3 common pattern.
In this patch,I replace filter(lambda obj: test(obj),data)
with[obj for obj in data if test(obj)]

Change-Id: I68e76f91dc31aa0e00124c1eb76a0a1f0178cc44

mistral/engine/dispatcher.py

@@ -49,7 +49,7 @@ def _rearrange_commands(cmds):
     """
 
     # Remove all 'noop' commands.
-    cmds = list(filter(lambda c: not isinstance(c, commands.Noop), cmds))
+    cmds = list([c for c in cmds if not isinstance(c, commands.Noop)])
 
     state_cmd_idx = -1
     state_cmd = None

mistral/engine/tasks.py

@@ -327,13 +327,9 @@ class RegularTask(Task):
         if self.reset_flag:
             execs = self.task_ex.executions
         else:
-            execs = filter(
-                lambda e: (
-                    e.accepted and
-                    e.state in [states.ERROR, states.CANCELLED]
-                ),
-                self.task_ex.executions
-            )
+            execs = [e for e in self.task_ex.executions if
+                     (e.accepted and
+                      e.state in [states.ERROR, states.CANCELLED])]
 
         for ex in execs:
             ex.accepted = False
@@ -598,7 +594,7 @@ class WithItemsTask(RegularTask):
         if list(filter(find_cancelled, self.task_ex.executions)):
             return True
 
-        execs = list(filter(lambda t: t.accepted, self.task_ex.executions))
+        execs = list([t for t in self.task_ex.executions if t.accepted])
         count = self._get_with_items_count() or 1
 
         # We need to make sure that method on_action_complete() has been
@@ -629,10 +625,8 @@ class WithItemsTask(RegularTask):
     def _get_accepted_executions(self):
         # Choose only if not accepted but completed.
         return list(
-            filter(
-                lambda x: x.accepted and states.is_completed(x.state),
-                self.task_ex.executions
-            )
+            [x for x in self.task_ex.executions
+             if x.accepted and states.is_completed(x.state)]
         )
 
     def _get_unaccepted_executions(self):

mistral/engine/workflows.py

@@ -165,7 +165,7 @@ class Workflow(object):
         # commands because workflow controller takes tasks that
         # completed within the period when the workflow was paused.
         cmds = list(
-            filter(lambda c: not isinstance(c, commands.PauseWorkflow), cmds)
+            [c for c in cmds if not isinstance(c, commands.PauseWorkflow)]
         )
 
         # Since there's no explicit task causing the operation

mistral/tests/unit/base.py

@@ -136,7 +136,7 @@ class BaseTest(base.BaseTestCase):
             return True
 
         filtered_items = list(
-            filter(lambda item: _matches(item, **props), items)
+            [item for item in items if _matches(item, **props)]
         )
 
         found = len(filtered_items)

mistral/workbook/v2/workflows.py

@@ -335,7 +335,7 @@ class DirectWorkflowSpec(WorkflowSpec):
 
     @staticmethod
     def _remove_task_from_clause(on_clause, t_name):
-        return list(filter(lambda tup: tup[0] != t_name, on_clause))
+        return list([tup for tup in on_clause if tup[0] != t_name])
 
 
 class ReverseWorkflowSpec(WorkflowSpec):

mistral_tempest_tests/services/base.py

@@ -41,7 +41,7 @@ def find_items(items, **props):
 
         return True
 
-    filtered = list(filter(lambda item: _matches(item, **props), items))
+    filtered = list([item for item in items if _matches(item, **props)])
 
     if len(filtered) == 1:
         return filtered[0]

mistral_tempest_tests/tests/scenario/engine/actions/v2/test_ssh_actions.py

@@ -79,7 +79,7 @@ class SSHActionsTestsV2(base.TestCaseAdvanced):
             'floating_ips'
         )
         free_ips = list(
-            filter(lambda fl_ip: fl_ip['instance_id'] is None, all_ips)
+            [fl_ip for fl_ip in all_ips if fl_ip['instance_id'] is None]
         )
 
         if free_ips: