python - 获取本地时区的 Olson TZ 名称？

Question

如何获得 Olson timezone name (如Australia/Sydney)对应C的localtime给出的值打电话？

这是通过 TZ、符号链接(symbolic link) /etc/localtime 或在与时间相关的系统配置中设置 TIMEZONE 变量覆盖的值文件。

Answer 1

我认为最好的办法是遍历所有 pytz 时区并检查哪个与本地时区匹配，每个 pytz 时区对象都包含有关 utcoffset 和 tzname 的信息，例如 CDT、EST，有关本地时间的相同信息可以从 time 获得.timezone/altzone 和 time.tzname，我认为这足以正确匹配 pytz 数据库中的本地时区，例如

import time
import pytz
import datetime

local_names = []
if time.daylight:
    local_offset = time.altzone
    localtz = time.tzname[1]
else:
    local_offset = time.timezone
    localtz = time.tzname[0]

local_offset = datetime.timedelta(seconds=-local_offset)

for name in pytz.all_timezones:
    timezone = pytz.timezone(name)
    if not hasattr(timezone, '_tzinfos'):
        continue#skip, if some timezone doesn't have info
    # go thru tzinfo and see if short name like EDT and offset matches
    for (utcoffset, daylight, tzname), _ in timezone._tzinfos.iteritems():
        if utcoffset == local_offset and tzname == localtz:
            local_names.append(name)

print local_names

输出:

['America/Atikokan', 'America/Bahia_Banderas', 'America/Bahia_Banderas', 'America/Belize', 'America/Cambridge_Bay', 'America/Cancun', 'America/Chicago', 'America/Chihuahua', 'America/Coral_Harbour', 'America/Costa_Rica', 'America/El_Salvador', 'America/Fort_Wayne', 'America/Guatemala', 'America/Indiana/Indianapolis', 'America/Indiana/Knox', 'America/Indiana/Marengo', 'America/Indiana/Marengo', 'America/Indiana/Petersburg', 'America/Indiana/Tell_City', 'America/Indiana/Vevay', 'America/Indiana/Vincennes', 'America/Indiana/Winamac', 'America/Indianapolis', 'America/Iqaluit', 'America/Kentucky/Louisville', 'America/Kentucky/Louisville', 'America/Kentucky/Monticello', 'America/Knox_IN', 'America/Louisville', 'America/Louisville', 'America/Managua', 'America/Matamoros', 'America/Menominee', 'America/Merida', 'America/Mexico_City', 'America/Monterrey', 'America/North_Dakota/Beulah', 'America/North_Dakota/Center', 'America/North_Dakota/New_Salem', 'America/Ojinaga', 'America/Pangnirtung', 'America/Rainy_River', 'America/Rankin_Inlet', 'America/Resolute', 'America/Resolute', 'America/Tegucigalpa', 'America/Winnipeg', 'CST6CDT', 'Canada/Central', 'Mexico/General', 'US/Central', 'US/East-Indiana', 'US/Indiana-Starke']

在生产中，您可以预先创建这样的映射并保存它，而不是总是迭代。

更改时区后的测试脚本:

$ export TZ='Australia/Sydney'
$ python get_tz_names.py
['Antarctica/Macquarie', 'Australia/ACT', 'Australia/Brisbane', 'Australia/Canberra', 'Australia/Currie', 'Australia/Hobart', 'Australia/Lindeman', 'Australia/Melbourne', 'Australia/NSW', 'Australia/Queensland', 'Australia/Sydney', 'Australia/Tasmania', 'Australia/Victoria']