Python日期时间如何在不同本地时区之间进行转换（+奖励DST）

Question

我有些困惑，不太明白为什么会得到这样的结果。

我想尝试的是:

1. Take two timezones, one that uses DST and one that doesn't. ex: Romania (dst) and Venezuela(no dst).

2. For the timezone that has dst, create two datetimes. One in the interval of the dst, and one that isn't. Romania DST interval (4-10 / April-October). Ex:

   from datetime import datetime
   from pytz import timezone
   
   tz1 = timezone('Europe/Bucharest')
   tz2 = timezone('America/Caracas')
   
   date1 = datetime(2016, 5, 5, 5, 0, 0, tzinfo=tz1)  # its in the dst interval (5 o'clock, summer - dst)
   date1 = datetime(2016, 12, 5, 5, 0, 0, tzinfo=tz1)  # isn't in the dst interval (5 o'clock, winter - no dst)
   
   x = date1.astimezone(tz2)
   y = date2.astimezone(tz2) 
   

3. Shouldn't x and y have different hours? Because date1 is in the DST interval, so 5 o'clock should mean a different hour than 5 o'clock in date2 when the datetime isn't in the DST interval.

然而，当转换为无夏令时时区时，x和y都具有相同的小时数。

感谢您提供的任何解释。

- El Dude Brother

Answer 1

如果要使用pytz时区，就不能使用datetime构造函数，而需要使用localize函数：

date1 = tz1.localize(datetime(2016, 5, 5, 5, 0, 0))
date2 = tz1.localize(datetime(2016, 12, 5, 5, 0, 0))

来自文档：

不幸的是，对于许多时区，使用标准datetime构造函数的tzinfo参数与pytz配合使用“无法正常工作”。

- Mark Ransom