题解 | #多报名表的运动项目人数统计#

import pandas as pd
items = pd.read_csv('items.csv')
signup = pd.read_csv('signup.csv')
signup1 = pd.read_csv('signup1.csv')
# 将signup.csv与signup1.csv的数据集合并
signAll = signup.merge(signup1, how='inner', on='item_id')
# 再次进行合并
merge1 = signAll.merge(items, how='inner', on='item_id')
# 对合并的数据进行分组，然后直接取不同值的次数
merge2 = merge1.groupby('item_name')['item_id'].nunique()
# 过滤不等于0的数据
print(merge2 != 0)