使用另一个if语句更新列表变量

Question

from datetime import datetime, date,time,timedelta
time1=[]
if not time1 : 
    timenow = datetime.now()
    time1.append(timenow)
    delta = timedelta(minutes=1)
    time1 =(time1[0]-delta).time()
    print("timestamp1 :",time1)
if (time1):
    timenow = datetime.now()
    time1.append(timenow) # updating time1 list , error in here
    delta = timedelta(minutes=1)
    time1 =(time1[0]+delta).time()
    print("update_timestamp :",time1)
    # if statement ():
        # do stuff

time1.append（timenow）

错误：

AttributeError: 'datetime.time' object has no attribute 'append'

关于使用另一个if语句更新time1列表是否有想法？