题解 | #牛客网每日正确与错误的答题次数#

import sys
import pandas as pd 
# nowcoder = pd.read_csv('nowcoder.csv')
# nowcoder.date = nowcoder.date.astype('str')
# where_time = nowcoder.date.apply(lambda x:x[0:7]) 
# nowcoder = nowcoder[where_time == '2021/12']#重要的是行数相同的True/False列表，可以不直接来自nowcoder
# nowcoder['year-month-day'] = pd.to_datetime(nowcoder.date,
#                                           format='%Y/%m/%d %H:%M').dt.date
fm=pd.read_csv('nowcoder.csv')
fm.date=pd.to_datetime(fm.date).dt.date
#或者用下面以扩列的方式命名新增整形列为year-month-day
#fm['year-month-day']=pd.to_datetime(fm.date).dt.date
#fm=fm[['result','date','question_id']].sort_values(by=['result','date'])
#Series必须是一个list
#因为Series的index必须与每个Value一一对应的所以行数多的时候都得用变量赋值index
Ss_fm=pd.Series(list(fm.question_id),index=[list(fm.result),list(fm.date)])#多级标签需要给多个list
Ss_fm.index.names=['result','year-month-day']#给含有多级index命名的属性不是index.name而是index.names
Ss_fm=Ss_fm.groupby(['result','year-month-day']).count()
print(Ss_fm)
for line in sys.stdin:
    a = line.split()
    print(int(a[0]) + int(a[1]))