python3 获取两个时间戳相差多少天和毫秒

import time
import datetime

t=datetime.datetime.now()

#当前日期
t1 =t.strftime('%Y-%m-%d %H:%M:%S')
#转为秒级时间戳
ts1=time.mktime(time.strptime(t1, '%Y-%m-%d %H:%M:%S'))
#转为毫秒级
end_time=int(str(ts1*1000).split(".")[0])


#48小时前
t2=(t-datetime.timedelta(hours=48)).strftime("%Y-%m-%d %H:%M:%S")
#转为秒级时间戳
ts2=time.mktime(time.strptime(t2, '%Y-%m-%d %H:%M:%S'))
#转为毫秒级
start_time=int(str(ts2*1000).split(".")[0])

print("\n","*"*30)

print(start_time)
print(time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(ts2)))

print("*"*30)

print(end_time)
print(time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(ts1)))

print("*"*30,"\n")

print("相差",(datetime.datetime.fromtimestamp(ts1)-datetime.datetime.fromtimestamp(ts2)).days,"天")


print("相差",(datetime.datetime.fromtimestamp(ts2)-datetime.datetime.fromtimestamp(ts1)).microseconds/1000.0,"ms")