diff --git a/.pylintrc b/.pylintrc
index 3a76fd6..3c5a2bd 100644
--- a/.pylintrc
+++ b/.pylintrc
@@ -82,7 +82,8 @@ disable=
  too-many-nested-blocks,
  too-many-public-methods,
  too-many-return-statements,
- too-many-statements
+ too-many-statements,
+ useless-object-inheritance
 
 [BASIC]
 # Variable names can be 1 to 31 characters long, with lowercase and underscores
diff --git a/oslogmerger/oslogmerger.py b/oslogmerger/oslogmerger.py
index 3ca70b2..68f3123 100644
--- a/oslogmerger/oslogmerger.py
+++ b/oslogmerger/oslogmerger.py
@@ -14,6 +14,7 @@
 #    under the License.
 
 from __future__ import print_function
+
 import argparse
 from datetime import datetime, timedelta
 import hashlib
@@ -110,7 +111,8 @@ class LogEntry(object):
         self.data += EXTRALINES_PADDING + line
 
     def __cmp__(self, other):
-        return cmp(self.dt, other.dt) * 2 + cmp(self.alias, other.alias)
+        return (self._cmp(self.dt, other.dt) * 2 +
+                self._cmp(self.alias, other.alias))
 
     def __lt__(self, other):
         return self.dt < other.dt or (self.dt == other.dt and
@@ -119,6 +121,10 @@ class LogEntry(object):
     def __str__(self):
         return '%s [%s] %s' % (self.dt_str, self.alias, self.data.rstrip('\n'))
 
+    @staticmethod
+    def _cmp(a, b):
+        return (a > b) - (a < b)
+
 
 class LogParser(object):
     def __init__(self, filename, cfg):
diff --git a/oslogmerger/probes/netprobe.py b/oslogmerger/probes/netprobe.py
index 87b7c1c..464bea2 100644
--- a/oslogmerger/probes/netprobe.py
+++ b/oslogmerger/probes/netprobe.py
@@ -135,7 +135,7 @@ the tcpdumps goes in a single openstack-like log.
 
     general_epilog = ""
 
-    parser = MyParser(description=general_description, version=__version__,
+    parser = MyParser(description=general_description,
                       epilog=general_epilog, argument_default='',
                       formatter_class=argparse.RawTextHelpFormatter)
     parser.add_argument('--netns-re', '-n', dest='netns_regex',
diff --git a/test-requirements.txt b/test-requirements.txt
index 9154faf..ee79074 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -2,10 +2,10 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 flake8
-flake8-import-order==0.12 # LGPLv3
+flake8-import-order # LGPLv3
 mock>=2.0.0 # BSD
 python-subunit>=0.0.18 # Apache-2.0/BSD
 testtools>=1.4.0 # MIT
 oslotest>=1.10.0 # Apache-2.0
 os-testr>=1.0.0 # Apache-2.0
-pylint==1.4.5 # GPLv2
+pylint # GPLv2
diff --git a/tox.ini b/tox.ini
index 872091e..d21efc8 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py35,py36,py27,pep8
+envlist = py35,py36,py37,py27,pep8
 minversion = 2.3.2
 skipsdist = True
 
@@ -24,7 +24,7 @@ setenv = OS_TEST_TIMEOUT={env:OS_TEST_TIMEOUT:180}
 commands = false
 
 [testenv:pep8]
-basepython = python2.7
+basepython = python3
 deps =
   {[testenv]deps}
 commands=