fix pep8

Author: charlesdong1991

pandas/tests/io/formats/test_format.py

@@ -2385,10 +2385,8 @@ def test_to_string_header(self):
         (['.1', '1'], '.1\n 1'),
         (['10', '-10'], ' 10\n-10')
     ])
-    def test_to_string_index_false_corner_case(self,
-                                              input_series,
-                                              expected):
-        s = pd.Series(input_series).to_string(index=False)
+    def test_to_string_index_false_corner_case(self, inputs, expected):
+        s = pd.Series(inputs).to_string(index=False)
         assert s == expected