Fixed PEP8 issues

Author: ante012

pandas/core/generic.py

@@ -4055,7 +4055,7 @@ def fillna(self, value=None, method=None, axis=None, inplace=False,
                     obj = result[k]
                     obj.fillna(v, limit=limit, inplace=True, downcast=downcast)
                 return result if not inplace else None
-                
+
             elif not is_list_like(value):
                 new_data = self._data.fillna(value=value, limit=limit,
                                              inplace=inplace,

pandas/tests/frame/test_missing.py

@@ -407,7 +407,7 @@ def test_fillna_inplace(self):
         df.fillna(value=0, inplace=True)
         tm.assert_frame_equal(df, expected)
 
-        expected = df.fillna(value={0 : 0}, inplace=True)
+        expected = df.fillna(value={0: 0}, inplace=True)
         assert expected is None
 
         df[1][:4] = np.nan