题解 | #统计运动会项目报名人数#

import pandas as pd
import datetime as dt

item = pd.read_csv("items.csv", sep=",")
sign = pd.read_csv("signup.csv", sep=",")

pd.set_option("display.width", 300)  # 设置字符显示宽度
pd.set_option("display.max_rows", None)  # 设置显示最大行
pd.set_option("display.max_columns", None)

itemcnt = sign.groupby("item_id").employee_id.count()
total = pd.merge(item, itemcnt, how="inner", on="item_id")
total.rename({"employee_id":"count"}, axis=1, inplace=True)
total.set_index('item_name',inplace=True)
print(total[total['count']>0]['count'])