diff --git a/tensorflow/python/estimator/inputs/pandas_io.py b/tensorflow/python/estimator/inputs/pandas_io.py
index a4963542679..af8030701be 100644
--- a/tensorflow/python/estimator/inputs/pandas_io.py
+++ b/tensorflow/python/estimator/inputs/pandas_io.py
@@ -111,7 +111,7 @@ def pandas_input_fn(x,
       raise ValueError('Index for x and y are mismatched.\nIndex for x: %s\n'
                        'Index for y: %s\n' % (x.index, y.index))
     if isinstance(y, pd.DataFrame):
-      y_columns = [(column, _get_unique_target_key(x, column)) 
+      y_columns = [(column, _get_unique_target_key(x, column))
                     for column in list(y)]
       target_column = [v for _, v in y_columns]
       x[target_column] = y