```
user_id create_time
0 38441 1541001602
1 38442 1541001664
2 38443 1541001744
3 38444 1541001926
4 38445 1541002012
5 38446 1541002413
6 38447 1541002444
7 38448 1541002530
8 38449 1541002593
```
转换成北京时间日期
userdf['date']= pd.to_datetime(userdf['create_time'].values, utc=True, unit='s').tz_convert(
"Asia/Shanghai").to_period("D")
user_id create_time date
0 38441 1541001602 2018-11-01
1 38442 1541001664 2018-11-01
2 38443 1541001744 2018-11-01
3 38444 1541001926 2018-11-01
4 38445 1541002012 2018-11-01
5 38446 1541002413 2018-11-01
6 38447 1541002444 2018-11-01
7 38448 1541002530 2018-11-01
8 38449 1541002593 2018-11-01
9 38450 1541002769 2018-11-01