turn lists of lists into strings pandas dataframe
问题 Background I have the following toy df that contains lists in the columns Before and After as seen below import pandas as pd before = [list(['in', 'the', 'bright', 'blue', 'box']), list(['because','they','go','really','fast']), list(['to','ride','and','have','fun'])] after = [list(['there', 'are', 'many', 'different']), list(['i','like','a','lot','of', 'sports']), list(['the','middle','east','has','many'])] df= pd.DataFrame({'Before' : before, 'After' : after, 'P_ID': [1,2,3], 'Word' : [