题解 | #牛客网每日正确与错误的答题次数#

import sys

for line in sys.stdin:
    a = line.split()
    print(int(a[0]) + int(a[1]))

import pandas as pd 
#读取文件
df=pd.read_csv('nowcoder.csv')
#把date列转换日期格式，并且在表中添加一列，列名year-month-day
df['year-month-day']=pd.to_datetime(df['date']).dt.date
#把date列转换日期格式，并赋值给date列（即覆盖）
df['date']=pd.to_datetime(df['date'],format='%Y-%m-%d')
#把date列设置为索引
df=df.set_index('date')
#排序
df=df.sort_values('date')
#筛选2021-12
df1=df['2021-12']
#按result，year-month-day这两列分组，统计结果
df2=df1.groupby(['result','year-month-day'])['user_id'].count()
print(df2)