diff --git a/.pylintrc b/.pylintrc
index 4f81533c..f493fbd3 100644
--- a/.pylintrc
+++ b/.pylintrc
@@ -6,19 +6,15 @@ jobs = 0
 disable =
     # TODO(ssbarnea): remove temporary skips adding during initial adoption:
     broad-except,
-    dangerous-default-value,
     duplicate-code,
     fixme,
-    function-redefined,
     global-statement,
-    inconsistent-return-statements,
     invalid-name,
     line-too-long,
     missing-class-docstring,
     missing-function-docstring,
     missing-module-docstring,
     no-member,
-    no-self-use,
     protected-access,
     redefined-outer-name,
     super-init-not-called,
diff --git a/elastic_recheck/cmd/cleanup.py b/elastic_recheck/cmd/cleanup.py
index 1877ede3..9dd0a19f 100644
--- a/elastic_recheck/cmd/cleanup.py
+++ b/elastic_recheck/cmd/cleanup.py
@@ -141,6 +141,7 @@ def main():
     if not cleaned:
         cleaned.append('None')
     info('%sRemoved queries:\n%s' % (prefix, '\n'.join(sorted(cleaned))))
+    return 0
 
 
 if __name__ == "__main__":
diff --git a/elastic_recheck/elasticRecheck.py b/elastic_recheck/elasticRecheck.py
index f99a0fb9..60e79e5e 100644
--- a/elastic_recheck/elasticRecheck.py
+++ b/elastic_recheck/elasticRecheck.py
@@ -105,7 +105,6 @@ class FailEvent(object):
     rev = None
     project = None
     url = None
-    build_short_uuids = []
     comment = None
     failed_jobs = []
 
diff --git a/elastic_recheck/results.py b/elastic_recheck/results.py
index bdefff46..b1fa410b 100644
--- a/elastic_recheck/results.py
+++ b/elastic_recheck/results.py
@@ -117,10 +117,10 @@ class ResultSet(list):
     (pyes goes way overboard with nesting, which is fine in the general
     case, but in the elastic_recheck case is just added complexity).
     """
-    def __init__(self, results={}):
-        self._results = results
-        if 'hits' in results:
-            self._parse_hits(results['hits'])
+    def __init__(self, results=None):
+        self._results = results or {}
+        if 'hits' in self._results:
+            self._parse_hits(self._results['hits'])
 
     def _parse_hits(self, hits):
         # why, oh why elastic search
@@ -139,6 +139,7 @@ class ResultSet(list):
                 return self._results['facets']['tag'][attr]
         if attr in self._results:
             return self._results[attr]
+        raise AttributeError(attr)
 
 
 class FacetSet(dict):
@@ -153,7 +154,8 @@ class FacetSet(dict):
 
     Treat this basically like a dictionary (which it inherits from).
     """
-    def _histogram(self, data, facet, res=3600):
+    @staticmethod
+    def _histogram(data, facet, res=3600):
         """A preprocessor for data should we want to bucket it."""
         # NOTE(mriedem): We sometimes hit a case where the @timestamp attribute
         # is too large and ES won't return it. At some point we should probably
diff --git a/elastic_recheck/tests/unit/test_bot.py b/elastic_recheck/tests/unit/test_bot.py
index b2b5dab5..653cb809 100644
--- a/elastic_recheck/tests/unit/test_bot.py
+++ b/elastic_recheck/tests/unit/test_bot.py
@@ -118,7 +118,8 @@ class TestBotWithTestTools(tests.TestCase):
                      "gate-keystone-python27: unrecognized error")
         self.assertEqual(reference, msg)
 
-    def fake_display(self, *args):
+    @staticmethod
+    def fake_display(*args):
         return True
 
     def test_error_found(self):