Fix python files in the 'examples' directory

Fix consists of following things:
- Add py2/3 compatibility
- Place imports into 3 different groups and reorder them alphabetically.
  As it is written in the "pep8" [1].

[1] https://www.python.org/dev/peps/pep-0008/

Change-Id: Iad1c6c409d2711f8c9b2d929d29072953fd49d8e
Signed-off-by: Valerii Ponomarov <kiparis.kh@gmail.com>

4 files changed, 69 insertions, 32 deletions

diff --git a/examples/test_baseclass_variables.py b/examples/test_baseclass_variables.py
index 86488d6bd..09a0ad9f1 100644
--- a/examples/test_baseclass_variables.py
+++ b/examples/test_baseclass_variables.py
@@ -1,10 +1,16 @@
 """ This Module demostrates how to use functions available in volume_ops
 """
 from glusto.core import Glusto as g
-from glustolibs.gluster.gluster_base_class import (GlusterBaseClass)
 
+from glustolibs.gluster.gluster_base_class import (
+    GlusterBaseClass,
+    runs_on,
+)
 
-class DemoGlusyerBaseClassVariables(GlusterBaseClass):
+
+@runs_on([['distributed-replicated', 'replicated'],
+          ['glusterfs', 'nfs']])
+class DemoGlusterBaseClassVariables(GlusterBaseClass):
     """Demonstrating all the functions available in volume_ops module
     """
     @classmethod
@@ -13,7 +19,7 @@ class DemoGlusyerBaseClassVariables(GlusterBaseClass):
         """
         # Read all the cluster config from the g.config and assign it to
         # class variables
-        GlusterBaseClass.setUpClass.im_func(cls)
+        cls.get_super_method(cls, 'setUpClass')()
 
         # Servers (list)
         g.log.info("Servers:\n %s\n\n", cls.servers)
diff --git a/examples/test_glusterd_ops.py b/examples/test_glusterd_ops.py
index 39cad7135..dc9bc2196 100644
--- a/examples/test_glusterd_ops.py
+++ b/examples/test_glusterd_ops.py
@@ -2,28 +2,39 @@
     module
 """
 from glusto.core import Glusto as g
-from glustolibs.gluster.gluster_base_class import GlusterBaseClass
+
 from glustolibs.gluster.exceptions import ExecutionError
+from glustolibs.gluster.gluster_base_class import (
+    GlusterBaseClass,
+    runs_on,
+)
 from glustolibs.gluster.gluster_init import (
-    is_glusterd_running, restart_glusterd, start_glusterd, stop_glusterd)
+    is_glusterd_running,
+    restart_glusterd,
+    start_glusterd,
+    stop_glusterd,
+)
 
 
+@runs_on([['distributed-replicated', 'replicated'],
+          ['glusterfs', 'nfs']])
 class DemoGlusterInitClass(GlusterBaseClass):
     """Demonstrating all the functions available in gluster_init module
     """
     @classmethod
     def setUpClass(cls):
-        """
+        """Define it when you need to execute something else than super's
+           setUpClass method.
         """
         # Read all the cluster config from the g.config and assign it to
         # class variables
-        GlusterBaseClass.setUpClass.im_func(cls)
+        cls.get_super_method(cls, 'setUpClass')()
 
     def setUp(self):
         """setUp required for tests
         """
         # Calling GlusterBaseClass setUp
-        GlusterBaseClass.setUp.im_func(self)
+        self.get_super_method(self, 'setUp')()
 
         # Check if glusterd is running on all servers(expected: active)
         g.log.info("Check if glusterd is running on all servers %s"
@@ -103,10 +114,11 @@ class DemoGlusterInitClass(GlusterBaseClass):
                    self.servers)
 
         # Calling GlusterBaseClass tearDown
-        GlusterBaseClass.tearDown.im_func(self)
+        self.get_super_method(self, 'tearDown')()
 
     @classmethod
     def tearDownClass(cls):
+        """Define it when you need to execute something else than super's
+           tearDownClass method.
         """
-        """
-        GlusterBaseClass.tearDownClass.im_func(cls)
+        cls.get_super_method(cls, 'tearDownClass')()
diff --git a/examples/test_peer_ops.py b/examples/test_peer_ops.py
index 12f3677fd..8a42f7070 100644
--- a/examples/test_peer_ops.py
+++ b/examples/test_peer_ops.py
@@ -1,28 +1,41 @@
 """ This Module demostrates how to use functions available in peer_ops module
 """
 
-import socket
 import random
 import re
+import socket
+
 from glusto.core import Glusto as g
-from glustolibs.gluster.gluster_base_class import GlusterBaseClass
+
 from glustolibs.gluster.exceptions import ExecutionError
+from glustolibs.gluster.gluster_base_class import (
+    GlusterBaseClass,
+    runs_on,
+)
 from glustolibs.gluster.peer_ops import (
-    pool_list, peer_probe, peer_status, peer_probe_servers,
-    nodes_from_pool_list, is_peer_connected, peer_detach, peer_detach_servers,
-    get_peer_status, get_pool_list)
-
-
+    get_peer_status,
+    get_pool_list,
+    is_peer_connected,
+    nodes_from_pool_list,
+    peer_detach,
+    peer_detach_servers,
+    peer_probe,
+    peer_probe_servers,
+    peer_status,
+    pool_list,
+)
+
+
+@runs_on([['distributed-replicated', 'replicated'],
+          ['glusterfs', 'nfs']])
 class DemoPeerOpsClass(GlusterBaseClass):
     """Demonstrating all the functions available in peer_ops module
     """
     @classmethod
     def setUpClass(cls):
-        """
-        """
         # Read all the cluster config from the g.config and assign it to
         # class variables
-        GlusterBaseClass.setUpClass.im_func(cls)
+        cls.get_super_method(cls, 'setUpClass')()
 
         # Detach all the servers if it's already attached to the cluster
         nodes_in_pool_list = nodes_from_pool_list(cls.mnode)
@@ -67,9 +80,8 @@ class DemoPeerOpsClass(GlusterBaseClass):
                        server, out)
 
     def setUp(self):
-        """
-        """
-        GlusterBaseClass.setUp.im_func(self)
+        self.get_super_method(self, 'setUp')()
+
         # Peer probe servers
         g.log.info("Peer Probe servers '%s'", self.servers)
         ret = peer_probe_servers(self.mnode, self.servers)
@@ -320,10 +332,11 @@ class DemoPeerOpsClass(GlusterBaseClass):
             g.log.info("Successfully detached servers %s from node %s",
                        nodes_in_pool_list, self.mnode)
 
-        GlusterBaseClass.tearDown.im_func(self)
+        self.get_super_method(self, 'tearDown')()
 
     @classmethod
     def tearDownClass(cls):
+        """Define it when you need to execute something else than super's
+           tearDownClass method.
         """
-        """
-        GlusterBaseClass.tearDownClass.im_func(cls)
+        cls.get_super_method(cls, 'tearDownClass')()
diff --git a/examples/tests_using_baseclass.py b/examples/tests_using_baseclass.py
index 569feac83..fecd412a1 100644
--- a/examples/tests_using_baseclass.py
+++ b/examples/tests_using_baseclass.py
@@ -14,7 +14,10 @@
 #  with this program; if not, write to the Free Software Foundation, Inc.,
 #  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
-from glustolibs.gluster.gluster_base_class import (GlusterBaseClass, runs_on)
+from glustolibs.gluster.gluster_base_class import (
+    GlusterBaseClass,
+    runs_on,
+)
 
 """ Example1: Using GlusterBaseClass
 """
@@ -33,7 +36,7 @@ class TestUsingGlusterBaseClass(GlusterBaseClass):
         # Calling GlusterBaseClass setUpClass. This will read all the
         # Variables from the g.config and will assign values to variables to
         # Use in the tests
-        GlusterBaseClass.setUpClass.im_func(cls)
+        cls.get_super_method(cls, 'setUpClass')()
 
         # Add test class setup code here.
 
@@ -41,7 +44,7 @@ class TestUsingGlusterBaseClass(GlusterBaseClass):
         """setUp before the test
         """
         # Calling GlusterBaseClass setUp
-        GlusterBaseClass.setUp.im_func(self)
+        self.get_super_method(self, 'setUp')()
 
         # Add test setup code here
 
@@ -60,13 +63,16 @@ class TestUsingGlusterBaseClass(GlusterBaseClass):
         # Add test teardown code here
 
         # Calling GlusterBaseClass teardown
-        GlusterBaseClass.tearDown.im_func(self)
+        self.get_super_method(self, 'tearDown')()
 
     @classmethod
     def tearDownClass(cls):
         """tearDownClass. This will be executed once per class.
+
+        Define it when you need to execute something else than super's
+        tearDownClass method.
         """
         # Add test class teardown code here
 
         # Calling GlusterBaseClass tearDownClass.
-        GlusterBaseClass.tearDownClass.im_func(cls)
+        cls.get_super_method(cls, 'tearDownClass')()