python int、string类型20200101转时间类型

import pandas as pd
import numpy as np
dic={
    
    'id':['a','b','c','d'],
     'time1':[20200101,20200102,20200103,20200104],
     'time2':['20200101','20200102','20200103','20200104']
     }
df=pd.DataFrame(dic)

# print(df)
df['time1']=pd.to_datetime(df['time1'].astype('string'))
df['time2']=pd.to_datetime(df['time2'])
print(df.info())

from datetime import datetime
from dateutil.relativedelta import relativedelta
d=datetime.now()   #取当前时间  2021-08-03 10:10:20
# print(da)
da=str(d)[:10]    #取年月日  2021-08-03
# print(da)
date=datetime.strptime(da,'%Y-%m-%d')   #转为时间时分秒2021-08-03 00:00:00  ！！！Y大写！！！！！！！！！
# print(date)
two_year_bf =datetime.strptime(da,'%Y-%m-%d')  - relativedelta(days=2)  #减2年 ,days,months,years,weeks。2021-08-01 00:00:00

print(two_year_bf)