如何将日期时间值更改为单独格式化的值

Question

我有一个数据集，不幸的是它有零星的日期时间值，而不是int或str

例如，我如何通过遍历数据库并将2019-05-03 00:00:00替换为5-3来编辑这些值

我尝试了一些循环，但没有效果。有捷径吗

,age,menopause,tumor-size,inv-nodes,node-caps,deg-malig,breast,breast-quad,irradiat,Class
0,40-49,premeno,15-19,0-2,yes,3,right,left_up,no,recurrence-events
1,50-59,ge40,15-19,0-2,no,1,right,central,no,no-recurrence-events
2,50-59,ge40,35-39,0-2,no,2,left,left_low,no,recurrence-events
3,40-49,premeno,35-39,0-2,yes,3,right,left_low,yes,no-recurrence-events
4,40-49,premeno,30-34,2019-05-03 00:00:00,yes,2,left,right_up,no,recurrence-events
5,50-59,premeno,25-29,2019-05-03 00:00:00,no,2,right,left_up,yes,no-recurrence-events
6,50-59,ge40,40-44,0-2,no,3,left,left_up,no,no-recurrence-events
7,40-49,premeno,2014-10-01 00:00:00,0-2,no,2,left,left_up,no,no-recurrence-events
8,40-49,premeno,0-4,0-2,no,2,right,right_low,no,no-recurrence-events
9,40-49,ge40,40-44,15-17,yes,2,right,left_up,yes,no-recurrence-events
10,50-59,premeno,25-29,0-2,no,2,left,left_low,no,no-recurrence-events
11,60-69,ge40,15-19,0-2,no,2,right,left_up,no,no-recurrence-events
12,50-59,ge40,30-34,0-2,no,1,right,central,no,no-recurrence-events
13,50-59,ge40,25-29,0-2,no,2,right,left_up,no,no-recurrence-events
14,40-49,premeno,25-29,0-2,no,2,left,left_low,yes,recurrence-events
15,30-39,premeno,20-24,0-2,no,3,left,central,no,no-recurrence-events
16,50-59,premeno,2014-10-01 00:00:00,2019-05-03 00:00:00,no,1,right,left_up,no,no-recurrence-events
17,60-69,ge40,15-19,0-2,no,2,right,left_up,no,no-recurrence-events
18,50-59,premeno,40-44,0-2,no,2,left,left_up,no,no-recurrence-events
19,50-59,ge40,20-24,0-2,no,3,left,left_up,no,no-recurrence-events
20,50-59,lt40,20-24,0-2,?,1,left,left_low,no,recurrence-events
21,60-69,ge40,40-44,2019-05-03 00:00:00,no,2,right,left_up,yes,no-recurrence-events
22,50-59,ge40,15-19,0-2,no,2,right,left_low,no,no-recurrence-events
23,40-49,premeno,2014-10-01 00:00:00,0-2,no,1,right,left_up,no,no-recurrence-events
24,30-39,premeno,15-19,2019-08-06 00:00:00,yes,3,left,left_low,yes,recurrence-events
25,50-59,ge40,20-24,2019-05-03 00:00:00,yes,2,right,left_up,no,no-recurrence-events

Answer 1

import re
import datetime 

s = "2014-10-01 00:00:00"

pattern = re.compile("\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}")

if pattern.match(s):
  d = datetime.datetime.strptime(s, "%Y-%m-%d %H:%M:%S")
  print(f"{str(d.month).zfill(2)}-{str(d.day).zfill(2)}")