根据网上的一些说法，
在python里获取ms级系统时间可以通过以下方式获取：
import datetime print(datetime.datetime.now().microsecond)
但通过以下代码测试，发现返回的并不是ms的值，而是us的值：
import datetime
def getTime_ms():
return (datetime.datetime.now().hour*3600 +\
datetime.datetime.now().minute*60+\
datetime.datetime.now().second )*1000+\
datetime.datetime.now().microsecond/1000
def timetime():
t = getTime_ms()
while getTime_ms() - t < 500:
pass
a = getTime_ms()
print(t, a, a- t)
if __name__ == '__main__':
from timeit import timeit
t = timeit('timetime()', 'from __main__ import timetime', number=1)
print(t)
打印结果
(35460614, 35461114, 500) 0.499531984329
上面实验不太直观，换一个直观点的：
def timetime():
t1 = datetime.datetime.now()
while 1:
t2 = datetime.datetime.now()
if (t2 - t1).microseconds >= 1:
print(t2,t2.microsecond,t1,t1.microsecond,(t2-t1).seconds)
break
if __name__ == '__main__':
from timeit import timeit
t = timeit('timetime()', 'from __main__ import timetime', number=1)
print(t)
#print (datetime.datetime.now())
输出
(datetime.datetime(2019, 4, 3, 10, 6, 20, 461882), 461882, datetime.datetime(2019, 4, 3, 10, 6, 20, 461863), 461863, 0) 7.10487365723e-05
def timetime():
t1 = datetime.datetime.now()
while 1:
t2 = datetime.datetime.now()
if (t2 - t1).microseconds >= 1000:
print(t2,t2.microsecond,t1,t1.microsecond,(t2-t1).seconds)
break
if __name__ == '__main__':
from timeit import timeit
t = timeit('timetime()', 'from __main__ import timetime', number=1)
print(t)
#print (datetime.datetime.now())
输出
(datetime.datetime(2019, 4, 3, 10, 13, 52, 76548), 76548, datetime.datetime(2019, 4, 3, 10, 13, 52, 75547), 75547, 0) 0.00104904174805
补充：Python datetime去除毫秒 返回当前时间
datetime模块返回当前时间
import datetime
if __name__ == '__main__':
a = datetime.datetime.now().replace(microsecond=0)
print(a, type(a))
运算结果：
2020-05-22 12:13:42 <class 'datetime.datetime'> Process finished with exit code 0
以上为个人经验，希望能给大家一个参考，也希望大家多多支持。如有错误或未考虑完全的地方，望不吝赐教。
