如何使用 Python3 将日期时间 ('2019-06-05T10:37:29.353+0100') 转换为 UTC 时间戳？

Question

我想将datetime，即2019-06-05T10:37:29.353+0100，转换为Python3中的UTC时间戳。

我了解+0100 代表时区。为什么+0100、+0200和+0300都转换为相同的时间戳？

如何将包含时区的 datetime 转换为 UTC 时间戳？

>>> d=datetime.datetime.strptime('2019-06-05T10:37:29.353+0100', '%Y-%m-%dT%H:%M:%S.%f%z')
>>> unixtime = time.mktime(d.timetuple())
>>> unixtime
1559723849.0
>>> d=datetime.datetime.strptime('2019-06-05T10:37:29.353+0200', '%Y-%m-%dT%H:%M:%S.%f%z')
>>> unixtime = time.mktime(d.timetuple())
>>> unixtime
1559723849.0
>>> d=datetime.datetime.strptime('2019-06-05T10:37:29.353+0300', '%Y-%m-%dT%H:%M:%S.%f%z')
>>> unixtime = time.mktime(d.timetuple())
>>> unixtime
1559723849.0

Answer 1

这里有一些更多的解释（见 cmets）如何在时间戳之间来回转换，作为带有 UTC 偏移量和 POSIX 时间戳的字符串。

from datetime import datetime, timezone

s = '2019-06-05T10:37:29.353+0100'
# to datetime object
dt = datetime.strptime('2019-06-05T10:37:29.353+0100', '%Y-%m-%dT%H:%M:%S.%f%z')
# note that the object has tzinfo set to a specific timedelta:
print(repr(dt))
>>> datetime.datetime(2019, 6, 5, 10, 37, 29, 353000, tzinfo=datetime.timezone(datetime.timedelta(seconds=3600)))

# you could store this info
dt_UTCoffset = dt.utcoffset() # datetime.timedelta(seconds=3600)

# to get POSIX seconds since the epoch:
ts = dt.timestamp()

# and back to datetime:
dt_from_ts = datetime.fromtimestamp(ts, tz=timezone.utc)
# note that this is a UTC timestamp; the UTC offset is zero:
print(dt_from_ts.isoformat())
>>> 2019-06-05T09:37:29.353000+00:00

# instead of UTC, you could also set a UTC offset:
dt_from_ts = datetime.fromtimestamp(ts, tz=timezone(dt_UTCoffset))
print(dt_from_ts.isoformat())
>>> 2019-06-05T10:37:29.353000+01:00

...关于在 Python 中使用 datetime 时的一个陷阱：如果您将时间戳转换为 datetime 并且不设置 tz 属性，则返回本地时间（同样适用于其他方式'轮！）：

print(datetime.fromtimestamp(ts)) # I'm on CEST at the moment, so UTC+2
>>> 2019-06-05 11:37:29.353000