On 1.5.x: ``` df = pd.DataFrame({'a': [1, 1, 2], 'b': [3, 4, 5]}).set_index(['a', 'b']) print(df.index.isin([])) # [False False False] ``` On 2.0.x: TypeError: Cannot infer number of levels from empty list Seems like an Index consisting of False is the right answer here.