python中datetime类型的utc时间如何转成时间戳？

Question

import datetime

now = datetime.datetime.utcnow()
这个now如何转成时间戳。。
用time.mktime(now.timetuple())这个方法产生的时间戳比time.time()产生的时间戳少28800秒，
现在我的方法是手动加上28800秒产生时间戳，，有没有更好的方法

Answer 1

雷雷

Answer 2

其实这里题主理解错了 mktime 的意思，我们来看一下 python 的官方文档：mktime 的意思，我们来看一下 python 的官方文档：

time.mktime(t)
This is the inverse function of localtime(). Its argument is the struct_time or full 9-tuple (since the dst flag is needed; use -1 as the dst flag if it is unknown) which expresses the time in local time, not UTC. It returns a floating point number, for compatibility with time(). If the input value cannot be represented as a valid time, either OverflowError or ValueError will be raised (which depends on whether the invalid value is caught by Python or the underlying C libraries). The earliest date for which it can generate a time is platform-dependent.

mktime

time.mktime(t)
This is the inverse function of localtime(). Its argument is the struct_time or full 9-tuple (since the dst flag is needed; use -1 as the dst flag if it is unknown) which expresses the time in local time, not UTC. It returns a floating point number, for compatibility with time(). If the input value cannot be represented as a valid time, either OverflowError or ValueError will be raised (which depends on whether the invalid value is caught by Python or the underlying C libraries). The earliest date for which it can generate a time is platform-dependent.

mktime 传递的应该是本地的时间，而不是 utc 时间，所以，如果你想获得指定 utc 时间的时间戳，简单点的方法有：

直接减 Unix 的时间戳开始时间，也就是

1. timestamp = (now - datetime(1970, 1, 1)).total_seconds()

转换成本地时间

🎜

now = datetime.datetime.now()
timestamp = time.mktime(now.timetuple())

🎜当然，方法是有很多的，这里只是列举两种比较容易理解的方法。如果想知道更多的内容，这里有个链接可以供题主参考：Converting datetime.date to UTC timestamp in Python🎜

Answer 3

@yylucifer 说的很好。 主要时timezone的转换问题。
对于你的问题，可以用下面方法

# 基本上相等，但是会由于计算的耗时导致无法完全相等
# time.timezone：The offset of the local (non-DST) timezone, in seconds west of UTC 
time.mktime(datetime.datetime.utcnow().timetuple()) == time.time() + time.timezone