import pandas as pd data=pd.read_csv('Nowcoder.csv',dtype=object) print(data.loc[:,['Nowcoder_ID','Level','Last_submission_time']]) data.Last_submission_time=pd.to_datetime(data.Last_submission_time,format='%Y-%m-%d') # print(data.Last_submission_time.str.extract('(\d{4})-(\d{2})-(\d(2))')) print(da...