Switch and/or to ternary operator

Since version 2.5 Python has had an official ternary operator, this
commit switches out the old and/or style for the more predictable
and readable official version.

Partial-Bug: #1663631

Change-Id: I064d842a6869d50fe232c7edf2b2202933027ec6

cinder/api/contrib/hosts.py

@@ -51,7 +51,7 @@ def _list_hosts(req, service=None):
     for host in services:
         delta = curr_time - (host.updated_at or host.created_at)
         alive = abs(delta.total_seconds()) <= CONF.service_down_time
-        status = (alive and "available") or "unavailable"
+        status = "available" if alive else "unavailable"
         active = 'enabled'
         if host.disabled:
             active = 'disabled'

cinder/api/contrib/services.py

@@ -77,7 +77,7 @@ class ServiceController(wsgi.Controller):
                 if abs(delta_sec) >= abs(delta_mod.total_seconds()):
                     updated_at = svc.modified_at
             alive = abs(delta_sec) <= CONF.service_down_time
-            art = (alive and "up") or "down"
+            art = "up" if alive else "down"
             active = 'enabled'
             if svc.disabled:
                 active = 'disabled'

cinder/test.py

@@ -302,7 +302,7 @@ class TestCase(testtools.TestCase):
             self.override_config(k, v)
 
     def start_service(self, name, host=None, **kwargs):
-        host = host and host or uuid.uuid4().hex
+        host = host if host else uuid.uuid4().hex
         kwargs.setdefault('host', host)
         kwargs.setdefault('binary', 'cinder-%s' % name)
         svc = service.Service.create(**kwargs)

cinder/tests/unit/volume/test_volume_migration.py

@@ -532,7 +532,7 @@ class VolumeMigrationTestCase(base.BaseVolumeTestCase):
                                         retyping=False,
                                         previous_status='available'):
 
-        initial_status = retyping and 'retyping' or status
+        initial_status = 'retyping' if retyping else status
         old_volume = tests_utils.create_volume(self.context, size=0,
                                                host=CONF.host,
                                                status=initial_status,