很多答案在python2中不起作用，或者没有从datetime中保存毫秒。这对我很有用

def datetime_to_ms_epoch(dt):
    microseconds = time.mktime(dt.timetuple()) * 1000000 + dt.microsecond
    return int(round(microseconds / float(1000)))

我是这样做的:

from datetime import datetime
from time import mktime

dt = datetime.now()
sec_since_epoch = mktime(dt.timetuple()) + dt.microsecond/1000000.0

millis_since_epoch = sec_since_epoch * 1000

你可以用德罗宁去时空旅行!

import datetime
import delorean
dt = datetime.datetime.utcnow()
delorean.Delorean(dt, timezone="UTC").epoch

http://delorean.readthedocs.org/en/latest/quickstart.html  

from datetime import datetime
from calendar import timegm

# Note: if you pass in a naive dttm object it's assumed to already be in UTC
def unix_time(dttm=None):
    if dttm is None:
       dttm = datetime.utcnow()

    return timegm(dttm.utctimetuple())

print "Unix time now: %d" % unix_time()
print "Unix timestamp from an existing dttm: %d" % unix_time(datetime(2014, 12, 30, 12, 0))

在Python 3.3中，添加了新的方法timestamp:

import datetime
seconds_since_epoch = datetime.datetime.now().timestamp()

你的问题说你需要毫秒，你可以得到这样的毫秒:

milliseconds_since_epoch = datetime.datetime.now().timestamp() * 1000

如果在naive datetime对象上使用时间戳，则假定该对象位于本地时区。如果您不希望发生这种情况，请使用时区感知的datetime对象。

在我看来，最简单的方法是

import datetime

epoch = datetime.datetime.utcfromtimestamp(0)

def unix_time_millis(dt):
    return (dt - epoch).total_seconds() * 1000.0