Мы уже знаем, что на текущую сессию интерпретатора изменение PYTHONPATH никак не повлияет. Но если вы запустите дочерний процесс, то он унаследует окружение текущего процесса, а значит и изменения в любых переменных будут на него влиять.
Вот небольшой пример:
Объявляем переменную
user@host:~$ export PYTHONPATH=/path1
Запускаем интерпретатор
user@host:~$ python3
Проверим что в sys.path
>>> import sys
>>> print(sys.path)
['', '/path1', '/usr/lib/...', ...]
Добавляем что-то в переменную
>>> import os
>>> os.emviron['PYTHONPATH'] = '/path1:/path2'
>>> print(sys.path)
['', '/path1', '/usr/lib/...', ...]
Изменений нет. Но давайте запустим дочерний процесс и посмотрим там
>>> os.system('python3')
# теперь мы находимся в другом процессе
>>> import sys
>>> print(sys.path)
['', '/path1', '/path2', '/usr/lib/...', ...]
Тоже самое будет и с subprocess, так как по умолчанию текущее окружение тоже наследуется.
>>> import subprocess
>>> subprocess.call(['python3', '-c', 'import sys;print(sys.path)'])
['', '/path1', '/path2', '/usr/lib/...', ...]
______________________
Лучшей практикой является передача энвайронмента явно через аргумент env!
import subprocess
subprocess.call(cmd, env={'PYTHONPATH': '...'})
Это поможет точно понимать какое окружение будет у запускаемого процесса и при этом не изменять окружение текущего процесса.
#basic
https://pypi.python.org/pypi/pytz?
#pytz brings the Olson tz database into Python. This library allows
accurate and cross platform #timezone calculations using Python 2.4
or higher. It also solves the issue of ambiguous times at the end
of daylight saving time, which you can read more about in the Python
Library Reference (`datetime.tzinfo`).
🌍 Some countries adjust their time zones by just a single minute. Venezuela, for example, once set its clocks to UTC−4:30, then shifted to UTC−4:00 for efficiency, creating rare minute-level changes. ✨
#timezone⚡#clocks⚡#geography⚡#nature⚡#earth
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🌍 China uses a single official time zone—Beijing Time—across its vast territory, even though natural time differs by up to four hours from east to west within the country. ✨
#timezone⚡#china⚡#geography⚡#nature⚡#earth
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🌍 Samoa and American Samoa are just 160 kilometers apart but are 24 hours apart on the calendar due to the International Date Line, making them neighbors living in different days. ✨
#timezone⚡#Pacific⚡#islands⚡#geography⚡#nature⚡#earth
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🌍 The Chatham Islands, east of New Zealand, use a unique time zone: Chatham Standard Time is 45 minutes ahead of New Zealand, making it one of the few zones offset by less than a full hour. ✨
#timezone⚡#islands⚡#Pacific⚡#geography⚡#nature⚡#earth
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🌍 Spain's Canary Islands, though just west of Africa, use the same time zone as mainland Spain. Their clocks are always one hour behind the rest of the country, bridging continents by time. ✨
#timezone⚡#islands⚡#clocks⚡#geography⚡#nature⚡#earth
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🌍 Samoa’s 2011 time zone shift moved it west of the International Date Line, so travelers flying there from the U.S. now skip a day entirely, making for a calendar jump like nowhere else. ✨
#timezone⚡#dateline⚡#pacific⚡#geography⚡#nature⚡#earth
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🌍 The South Pole uses Coordinated Universal Time (UTC) for convenience, even though all lines of longitude—and thus every time zone—meet at this single icy point on Earth. ✨
#timezone⚡#Antarctica⚡#poles⚡#geography⚡#nature⚡#earth
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🌍 Chile’s unique Easter Island uses UTC–6 time zone, two hours behind mainland Chile. This rare split lets sunrise and sunset times align better with local daylight on the remote Pacific island. ✨
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🌍 Central Australia uses a rare time zone offset of UTC+9:30. This half-hour difference was chosen to better match daylight with daily activities across vast, sparsely populated regions. ✨
#timezone⚡#Australia⚡#daylight⚡#geography⚡#nature⚡#earth
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China uses one official time zone: China Standard Time (CST), 8 hours ahead of UTC, called Beijing Time. In Xinjiang, many Uyghurs use Xinjiang Time, 2 hours behind CST. China does not change clocks for Daylight Saving Time.
To see the current time check [here]
@googlefactss⏰🇨🇳
#China#TimeZone#CST#Xinjiang#BeijingTime#funfact