dict_ = {
          'stu':['a','b','a','b','c'],
          'fav':['fa','fb','faa','fbb','fc']
        }

df_ = pd.DataFrame(dict_)

print(df_)
#输出内容:

 

 

# 通过 groupby apply 加lambda实现group_contact

print(df_.groupby('stu').apply(lambda x: ','.join(x.fav)))

 

 

当然这样也可以实现:

print(df_.groupby('stu').apply(lambda x: list(x.fav)))
或则:

print(df_.groupby('stu').agg({'fav' : lambda x: ', '.join(x)}))