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
data = pd.read_csv('signup.csv')
data1 = pd.read_csv('items.csv')
merge1 = pd.merge(left = data, right = data1, how = 'inner', left_on = 'item_id', right_on = 'item_id')
merge2 = merge1.groupby('item_name')['employee_id'].nunique()
print(merge2[merge2>0])