题解 | 统计运动会项目报名人数
统计运动会项目报名人数
https://www.nowcoder.com/practice/f992129b6da245d5bc5efb2f95289516
import pandas as pd item = pd.read_csv("items.csv") signup = pd.read_csv("signup.csv") data = pd.merge(item, signup, on="item_id") a = data.groupby(by="item_name")["employee_id"].apply("count") print(a)