zealerzhang: [code=python] Traceback (most recent call last): File "hebing.py", line 18, in File "D:\ProgramData\Anaconda3\lib\site-packages\pandas\core\frame.py", line 7297, in merge validate=validate, File "D:\ProgramData\Anaconda3\lib\site-packages\pandas\core\reshape\merge.py", line 86, in merge validate=validate, File "D:\ProgramData\Anaconda3\lib\site-packages\pandas\core\reshape\merge.py", line 620, in __init__ self._validate_specification() File "D:\ProgramData\Anaconda3\lib\site-packages\pandas\core\reshape\merge.py", line 1198, in _validate_specification ridx=self.right_index, pandas.errors.MergeError: No common columns to perform merge on. Merge options: left_on=None, right_on=None, left_index=False, right_index=False [/code]