toolchain-utils: fix cros lint and some random errors

We have enabled --py3 for cros lint and thus reveals some new linting
errors in migrated scripts. This patch fixes them and some other random
errors.

BUG=chromium:1011676
TEST=Passed unittests.

Change-Id: If129e01c21845e1b944a2b64e50e9fed7138c845
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/2055972
Tested-by: Zhizhou Yang <zhizhouy@google.com>
Reviewed-by: George Burgess <gbiv@chromium.org>
Commit-Queue: Zhizhou Yang <zhizhouy@google.com>
Auto-Submit: Zhizhou Yang <zhizhouy@google.com>

5 files changed, 4 insertions, 9 deletions

diff --git a/cros_utils/buildbot_utils.py b/cros_utils/buildbot_utils.py
index a06abd26..428433db 100644
--- a/cros_utils/buildbot_utils.py
+++ b/cros_utils/buildbot_utils.py
@@ -27,7 +27,6 @@ TIME_OUT = 43200  # Decide the build is dead or will never finish
 
 class BuildbotTimeout(Exception):
   """Exception to throw when a buildbot operation timesout."""
-  pass
 
 
 def RunCommandInPath(path, cmd):
diff --git a/cros_utils/device_setup_utils_unittest.py b/cros_utils/device_setup_utils_unittest.py
index 63f9bf66..12a70811 100755
--- a/cros_utils/device_setup_utils_unittest.py
+++ b/cros_utils/device_setup_utils_unittest.py
@@ -14,10 +14,9 @@ import time
 import unittest
 from unittest import mock
 
-from device_setup_utils import DutWrapper
-
 from cros_utils import command_executer
 from cros_utils import logger
+from cros_utils.device_setup_utils import DutWrapper
 
 BIG_LITTLE_CPUINFO = """processor       : 0
 model name      : ARMv8 Processor rev 4 (v8l)
diff --git a/cros_utils/logger.py b/cros_utils/logger.py
index 4cc4618e..e304fe12 100644
--- a/cros_utils/logger.py
+++ b/cros_utils/logger.py
@@ -207,7 +207,6 @@ class MockLogger(object):
   def __init__(self, *_args, **_kwargs):
     self.stdout = sys.stdout
     self.stderr = sys.stderr
-    return None
 
   def _AddSuffix(self, basename, suffix):
     return '%s%s' % (basename, suffix)
diff --git a/cros_utils/misc.py b/cros_utils/misc.py
index 246767f0..b4beb60c 100644
--- a/cros_utils/misc.py
+++ b/cros_utils/misc.py
@@ -462,7 +462,7 @@ def ApplyGerritPatches(chromeos_root, gerrit_patch_string,
   sys.path.append(os.path.join(chromeos_root, 'chromite'))
   # Imports below are ok after modifying path to add chromite.
   # Pylint cannot detect that and complains.
-  # pylint: disable=import-error
+  # pylint: disable=import-error, import-outside-toplevel
   from lib import git
   from lib import gerrit
   manifest = git.ManifestCheckout(chromeos_root)
diff --git a/cros_utils/tabulator.py b/cros_utils/tabulator.py
index 300c2d79..5029ceee 100644
--- a/cros_utils/tabulator.py
+++ b/cros_utils/tabulator.py
@@ -318,7 +318,7 @@ class SamplesTableGenerator(TableGenerator):
               v.append(None)
               run_fail += 1
           one_tuple = ((run_pass, run_fail), v)
-          if iterations != 0 and iterations != run_pass + run_fail:
+          if iterations not in (0, run_pass + run_fail):
             raise ValueError('Iterations of each benchmark run ' \
                              'are not the same')
           iterations = run_pass + run_fail
@@ -358,7 +358,7 @@ class SamplesTableGenerator(TableGenerator):
             # Accumulate each run result to composite benchmark run
             # If any run fails, then we set this run for composite benchmark
             # to None so that we know it fails.
-            if bench_runs[index] and row[label_index][index] != None:
+            if bench_runs[index] and row[label_index][index] is not None:
               row[label_index][index] += bench_runs[index]
             else:
               row[label_index][index] = None
@@ -557,12 +557,10 @@ class AmeanResult(StringMeanResult):
 
 class RawResult(Result):
   """Raw result."""
-  pass
 
 
 class IterationResult(Result):
   """Iteration result."""
-  pass
 
 
 class MinResult(Result):