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') data_s = pd.concat([signup, signup1], axis=0) # 按行拼接两个表 data = pd.merge(data_s, items, on='item_id', how='inner') print(data.groupby('item_name')['employee_id'].count())