题解 | #统计运动会项目报名人数(二)#

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)

sign_gp=sign.groupby('item_id').employee_id.count()
total=pd.merge(item,sign_gp,how='inner',on='item_id')
total.rename({'employee_id':'sign_cnt'},axis=1 ,inplace=True)
total.sign_cnt.fillna(0)
total.set_index('item_name',inplace=True)

print(total.sign_cnt)