题解 | #牛客网每日正确与错误的答题次数#

1、首先过一次筛选，新建一列year-month-day
2、然后选取日期前半部分并将str再转换成日期格式
3、然后用groupby函数对result和year-month-day列进行分组
4、并在最后计数时选择用question_id

import pandas as pd
nowcoder = pd.read_csv('nowcoder.csv')
nowcoder['year-month-day'] = pd.to_datetime(nowcoder.date.str[:10])
a = nowcoder.groupby(['result','year-month-day']).count().question_id
print(a)