Remove all usage of six library

Replace six with Python 3 style code.

Change-Id: I4b97e040f3e790ac114dcd43c68e6b67b1079adf

3 files changed, 3 insertions, 5 deletions

diff --git a/tools/colorizer.py b/tools/colorizer.py
index 7824b8c..2a667b4 100755
--- a/tools/colorizer.py
+++ b/tools/colorizer.py
@@ -46,7 +46,6 @@ import subunit
 import sys
 import unittest
 
-import six
 import testtools
 
 
@@ -277,7 +276,7 @@ class NovaTestResult(testtools.TestResult):
         self.stopTestRun()
 
     def stopTestRun(self):
-        for cls in list(six.iterkeys(self.results)):
+        for cls in list(self.results.keys()):
             self.writeTestCase(cls)
         self.stream.writeln()
         self.writeSlowTests()
diff --git a/tools/install_venv.py b/tools/install_venv.py
index 03fe5af..4ff48a2 100644
--- a/tools/install_venv.py
+++ b/tools/install_venv.py
@@ -18,11 +18,10 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import configparser
 import os
 import sys
 
-from six.moves import configparser
-
 import install_venv_common as install_venv
 
 
diff --git a/tools/lintstack.py b/tools/lintstack.py
index 1ae34d7..1f7923a 100755
--- a/tools/lintstack.py
+++ b/tools/lintstack.py
@@ -16,13 +16,13 @@
 
 """pylint error checking."""
 
+from io import StringIO
 import json
 import re
 import sys
 
 from pylint import lint
 from pylint.reporters import text
-from six.moves import cStringIO as StringIO
 
 ignore_codes = [
     # Note(maoy): E1103 is error code related to partial type inference