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
df_1 = pd.read_csv('items.csv')
df_2 = pd.read_csv('signup.csv')
df_3 = df_2.merge(df_1,left_on='item_id',right_on='item_id')
df = df_3.groupby('item_name')['employee_id'].count()
print(df[df != 0])
