TGINSIGHT SIMILAR POSTS
Изворен канал @pythonotes · Post #303 · 27 дек.
Наверняка вы замечали, что в Python есть удобная функция для получения переменной окружения os.getenv(NAME) И её "сестра" для создания или изменения переменных окружения os.putenv(NAME, VALUE) Но почему-то putenv() не работает как должно. Энвайромент не обновляется! os.putenv('MYVAR', '1') print(os.getenv('MYVAR')) ... и ничего 😴 Почему так? На самом деле энвайромент обновляется, но это значение не добавляется в словарь os.environ. Откройте исходник функции os.getenv(). Это просто шорткат для os.environ.get() В то время как putenv() это built-in С-функция. Словарь os.environ (или точней класс из MutableMapping) создаётся из энвайромента в момент инициализации. Функция putenv() самостоятельно его не изменяет. В тоже время, когда вы создаёте или изменяете ключ в os.environ, автоматически вызывается putenv() в методе __setitem__(). То есть, технически putenv() всё делает верно, но в os.environ это не отражается. Можно проверить так: >>> os.putenv('MYVAR', '123') >>> os.system('python -c "import os;print(os.getenv(\'MYVAR\'))"') 123 Я объявил переменную в текущем процессе и вызвал дочерний процесс, который её унаследовал и получил в составе os.environ. Аналогично при удалении переменной вызывается еще одна built-in функция unsetenv(), удаляющая переменную из системы. Итого ▫️ Удобней всего явно обновлять переменные через os.environ ▫️ Есть способ неявно создать/удалить переменную через putenv/unsetenv, что не повлияет на os.environ но изменит энвайромент и передаст изменения сабпроцессам. Но так лучше не делать! ▫️os.environ это просто обертка для built-in функций putenv() и unsetenv(). #basic
Hashtags
Пребарај: #smrt
@sgmrt · Post #2401 · 25.07.2025 г., 02:59
Train services on the North-South, East-West, Circle & Thomson-East Coast Lines, and some bus services will be extended on the eve of National Day, 8 Aug 2025 (Fri) (after midnight*). See poster for more info! 🇸🇬*Except Circle Line, due to temporary early closure.#SMRThttps://bit.ly/4o5W1RD - SMRT
Hashtags
@sgmrt · Post #2289 · 25.03.2025 г., 04:24
Train services on the North-South, East-West, Circle & Thomson-East Coast Lines, and some bus services will be extended for commuters travelling late on the eve of Hari Raya Puasa, 30 Mar 2025 (after midnight). Refer to the poster for more info. #SMRThttps://bit.ly/4lcEuGe - SMRT
Hashtags
@sgmrt · Post #1773 · 25.08.2023 г., 07:03
Train services on the 🚊 North-South, East-West, Circle & Thomson-East Coast Lines, and some 🚍 bus services will be extended for commuters travelling late during the Formula 1 Grand Prix on 15 - 17 Sep (Fri - Sun). 🏁🏎 See the poster for more info. 👀#SMRThttps://bit.ly/45pBZrD - SMRT
Hashtags
@sgmrt · Post #1758 · 25.07.2023 г., 02:08
Onward as one!🦁 Train services on the 🚊North-South, East-West, Circle & Thomson-East Coast Lines, and some 🚍bus services will be extended for commuters travelling late on the eve of National Day (8 Aug). 🇸🇬💗 Ref to the poster for more info. 👀#SMRThttps://bit.ly/3O5oUfJ - SMRT
Hashtags
@sgmrt · Post #2406 · 29.07.2025 г., 02:44
Train services on the 🚆 North-South, East-West, Circle & Thomson-East Coast Lines, and some 🚍 bus services will be extended for commuters travelling late on the eve of National Day, 8 Aug 2025 (Fri). 🇸🇬Please refer to the poster for more info. 👀#SMRT#AllAboutTrainshttps://bit.ly/4lTHYxg - SMRT
Hashtags
@sgmrt · Post #2405 · 29.07.2025 г., 02:39
Train services on the 🚆 North-South, East-West, Circle & Thomson-East Coast Lines, and some 🚍 bus services will be extended for commuters travelling late on the eve of National Day, 8 Aug 2025 (Fri). 🇸🇬Please refer to the poster for more info. 👀#SMRT#AllAboutTrains - SMRT
Hashtags
@sgmrt · Post #2354 · 26.05.2025 г., 09:04
Train services on the North-South, East-West, Circle & Thomson-East Coast Lines, and some bus services will be extended for commuters travelling late on the eve of Hari Raya Haji, 6 Jun 2025 (Fri) (after midnight). Refer to the poster for more info. #SMRT#AllAboutTrainshttps://bit.ly/4kcRGdi - SMRT
Hashtags
@sgmrt · Post #2334 · 06.05.2025 г., 09:59
Train services on the North-South, East-West, Circle & Thomson-East Coast Lines, and some bus services will be extended for commuters travelling late on the eve of Vesak Day, 11 May 2025 (Sun) (after midnight). Refer to the poster for more info. #SMRT#AllAboutTrainshttps://bit.ly/4k8NOtm - SMRT
Hashtags
@sgmrt · Post #2230 · 22.01.2025 г., 03:44
Train services on the North-South, East-West, Circle & Thomson-East Coast Lines, and some bus services will be extended for commuters travelling late on the eve of Chinese New Year, 28 Jan (after midnight). See poster for more info.🧧#SMRT#AllAboutTrains#AllAboutBuseshttps://bit.ly/4g6JEzO - SMRT
@sgmrt · Post #2157 · 17.10.2024 г., 03:09
Train services on NSEWL, CCL, TEL and some bus services will be extended for commuters travelling late on the eve of Deepavali, 30 Oct 2024 (Wed). 🪔 See the poster for more info! 👀#SMRT#AllAboutTrains#AllAboutBuseshttps://bit.ly/4dKOXni - SMRT
@sgmrt · Post #1947 · 31.05.2024 г., 02:09
Train services on the North-South, East-West, Circle & Thomson-East Coast Lines, and some bus services will be extended for commuters travelling late on the eve of Hari Raya Haji, 16 Jun 2024 (after midnight). Ref to the poster for more info. #SMRT#AllAboutTrains#AllAboutBuseshttps://bit.ly/4bWEkx9 - SMRT
@sgmrt · Post #1902 · 04.04.2024 г., 02:29
Train services on North-South, East-West, Circle & Thomson-East Coast Lines, and some bus services will be extended for commuters travelling late on eve of Hari Raya Puasa, 9 Apr 2024 (after midnight). Ref to the poster for more info. #SMRT#AllAboutTrains#AllAboutBuseshttps://bit.ly/3vLtQRF - SMRT