Clean imports in code

1. What is the problem
Some source files are still importing objects instead of modules

2. What is the solution to the problem
This patch set modifies lines which are importing objects
instead of modules. As per openstack import guide lines, user should
import modules in a file not objects.

http://docs.openstack.org/developer/hacking/#imports

3. What the features need to be implemented to the Tricircle
N/A.

Change-Id: Ib84188a761ad7403ee72f5336b631235ea5dda90

tricircle/common/httpclient.py

@@ -15,8 +15,7 @@
 
 from six.moves.urllib import parse as urlparse
 
-from requests import Request
-from requests import Session
+import requests
 
 from oslo_log import log as logging
 
@@ -141,10 +140,10 @@ def get_pod_service_ctx(context, t_url, region_name, s_type=cons.ST_NEUTRON):
 
 
 def forward_req(context, action, b_headers, b_url, b_body):
-    s = Session()
-    req = Request(action, b_url,
-                  data=b_body,
-                  headers=b_headers)
+    s = requests.Session()
+    req = requests.Request(action, b_url,
+                           data=b_body,
+                           headers=b_headers)
     prepped = req.prepare()
 
     # do something with prepped.body

tricircle/common/serializer.py

@@ -14,7 +14,7 @@
 # limitations under the License.
 import six
 
-from oslo_messaging import Serializer
+from oslo_messaging import serializer
 
 ATTR_NOT_SPECIFIED = object()
 
@@ -31,7 +31,7 @@ _SINGLETON_MAPPING = Mapping({
 })
 
 
-class TricircleSerializer(Serializer):
+class TricircleSerializer(serializer.Serializer):
     def __init__(self, base=None):
         super(TricircleSerializer, self).__init__()
         self._base = base

tricircle/xjob/xservice.py

@@ -32,10 +32,10 @@ from tricircle.common import rpc
 from tricircle.common import version
 
 
-from tricircle.common.serializer import TricircleSerializer as Serializer
+from tricircle.common import serializer as t_serializer
 
 from tricircle.common import topics
-from tricircle.xjob.xmanager import XManager
+from tricircle.xjob import xmanager as t_xmanager
 
 
 _TIMER_INTERVAL = 30
@@ -231,7 +231,7 @@ def create_service():
 
     LOG.debug(_('create xjob server'))
 
-    xmanager = XManager()
+    xmanager = t_xmanager.XManager()
     xservice = XService(
         host=CONF.host,
         binary="xjob",
@@ -240,7 +240,7 @@ def create_service():
         periodic_enable=True,
         report_interval=_TIMER_INTERVAL,
         periodic_interval_max=_TIMER_INTERVAL_MAX,
-        serializer=Serializer()
+        serializer=t_serializer.TricircleSerializer()
     )
 
     xservice.start()