Fix some pylint warnings.
diff --git a/yapf/__main__.py b/yapf/__main__.py
index 88f1ec6..2ebc7a6 100644
--- a/yapf/__main__.py
+++ b/yapf/__main__.py
@@ -11,6 +11,8 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+"""Main entry point."""
+# pylint: disable=invalid-name
 import yapf
 
 yapf.run_main()
diff --git a/yapf/yapflib/pytree_utils.py b/yapf/yapflib/pytree_utils.py
index be81775..417bdb1 100644
--- a/yapf/yapflib/pytree_utils.py
+++ b/yapf/yapflib/pytree_utils.py
@@ -269,7 +269,7 @@
     The string representation.
   """
   if isinstance(node, pytree.Leaf):
-    fmt = ('{name}({value}) [lineno={lineno}, column={column}, ' +
+    fmt = ('{name}({value}) [lineno={lineno}, column={column}, '
            'prefix={prefix}, penalty={penalty}]')
     return fmt.format(
         name=NodeName(node),
diff --git a/yapftests/main_test.py b/yapftests/main_test.py
index 95e1991..508c02c 100644
--- a/yapftests/main_test.py
+++ b/yapftests/main_test.py
@@ -123,7 +123,7 @@
   def testEchoBadInput(self):
     bad_syntax = '  a = 1\n'
     with patched_input(bad_syntax):
-      with captured_output() as (out, _):
+      with captured_output() as (_, _):
         with self.assertRaisesRegexp(SyntaxError, 'unexpected indent'):
           yapf.main([])
 
diff --git a/yapftests/reformatter_python3_test.py b/yapftests/reformatter_python3_test.py
index bd0c211..c6a3e99 100644
--- a/yapftests/reformatter_python3_test.py
+++ b/yapftests/reformatter_python3_test.py
@@ -245,7 +245,7 @@
     uwlines = yapf_test_helper.ParseAndUnwrap(unformatted_code)
     self.assertCodeEqual(expected_formatted_code, reformatter.Reformat(uwlines))
 
-  def testNoSpacesAroundPowerOparator(self):
+  def testSplittingArguments(self):
     if sys.version_info[1] < 5:
       return
     try: