Finding the column in a Pandas DataFrame that contains a list with only one element

import pandas as pd # Example DataFrame with a column containing lists df = pd.DataFrame({'Column1': [[1, 2], [3], [4, 5]], 'Column2': [[6, 7], [8, 9], [10]]}) # Find the column with lists of length 1 result = df.apply(lambda x: x.str.len() == 1).a...