Join dataframes - one with multiindex columns and the other without
问题 I'm trying to join two dataframes - one with multiindex columns and the other with a single column name. They have similar index. I get the following warning: "UserWarning: merging between different levels can give an unintended result (3 levels on the left, 1 on the right)" For example: arrays = [['bar', 'bar', 'baz', 'baz', 'foo', 'foo', 'qux', 'qux'], ['one', 'two', 'one', 'two', 'one', 'two', 'one', 'two']] tuples = list(zip(*arrays)) index = pd.MultiIndex.from_tuples(tuples, names=[