通过 Python，当系统时钟是 UTC 时，根据 DST 调整本地时间？ 必须使用时间模块而不是日期时间

Question

Via Python, get local time adjusted for DST, when system clock is UTC? Must use time module not datetime.

Using time.localtime() for returns UTC not local time. So how do you use time module in python to get DST adjusted local time when system clock is UTC?

Answer 1

I assume by "system time is in UTC" you mean "the environment is not configured to use a time zone". You can set the time zone manually from Python. ( bash example)

import os
import time

os.environ['TZ'] = 'Asia/Tokyo'
time.tzset()
print(time.localtime())
# => time.struct_time(tm_year=2021, tm_mon=7, tm_mday=16, tm_hour=9, tm_min=42, tm_sec=58, tm_wday=4, tm_yday=197, tm_isdst=0)

os.environ['TZ'] = 'US/Alaska'
time.tzset()
print(time.localtime())
# => time.struct_time(tm_year=2021, tm_mon=7, tm_mday=15, tm_hour=16, tm_min=42, tm_sec=58, tm_wday=3, tm_yday=196, tm_isdst=1)

If your environment is limited, you may not have the timezone info files at /usr/share/zoneinfo . You can either copy the files you will need (eg /usr/share/zoneinfo/Asia/Tokyo ), or you may define your TZ manually. See time.tzset() for more details.

Obviously, you can also set the TZ environment variable before you start your program, in which case importing os will not be necessary:

TZ=Asia/Tokyo python ....
TZ=US/Alaska python ....

or

export TZ=Asia/Tokyo
python ...

export TZ=US/Alaska
python ...