Fix Python linting issues in Python scripts

Fixed pylint issues for categories len-as-condition, using-constant-test,
undefined-variable and reimported.

Change-Id: Idad710958c3ca0ac6da78fb4709da03e5f079b34
Issue-ID: INT-1427
Signed-off-by: Bartek Grzybowski <b.grzybowski@partner.samsung.com>
diff --git a/test/vcpe/csar_parser.py b/test/vcpe/csar_parser.py
index da6fa43..da1903c 100755
--- a/test/vcpe/csar_parser.py
+++ b/test/vcpe/csar_parser.py
@@ -178,7 +178,7 @@
             },
         """
         node_dic = svc_template['topology_template']['groups']
-        for node_name, v in node_dic.items():
+        for node_name, v in node_dic.items(): # pylint: disable=W0612
             if v['type'].startswith('org.openecomp.groups.VfModule'):
                 model = {
                     'modelType': 'vfModule',