题解 | #统计运动会项目报名人数(二)#
统计运动会项目报名人数(二)
https://www.nowcoder.com/practice/737d224c9cce482fb56ff812d04e79ab
import pandas as pd item = pd.read_csv("items.csv") signup = pd.read_csv('signup.csv') a = pd.merge(item,signup,on='item_id') g = a.groupby(by="item_name")['item_id'].apply('count') print(g)