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Изворен канал @pythonotes · Post #32 · 7 фев.

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Скорее всего уже слышали, что складывать строки через + это плохая практика. Падение производительности, и всё такое. Без лишних слов, давайте измерять: from timeit import timeit def t1(): # складываем 10 строк через + из переменной t = 'text' for _ in range(1000): s = t + t + t + t + t + t + t + t + t def t2(): # склеиваем список строк через метод join arr = ['text'] * 10 for _ in range(1000): s = ''.join(arr) def t3(): # складываем через + но не из переменной а непосредственно инлайн объекты for _ in range(1000): s = 'text' + 'text' + 'text' + ... # всего 10 раз Теперь каждую строку склейки запустим по 10М раз >>> timeit(t1, number=10000) 0.21951690399964718 >>> timeit(t2, number=10000) 1.4978306379998685 >>> timeit(t3, number=10000) 0.2213820789993406 Хм, а нам говорили что через "+" это плохо и медленно ))) 😁 Тут стоит учитывать, что речь идёт о склейке множества длинных строк. Давайте изменим условия: def t4(): t = 'text'*100 for _ in range(1000): s = t + t + t + t + t + t + t + t + t def t5(): arr = ['text'*100] * 10 for _ in range(1000): s = ''.join(arr) def t6(): for _ in range(1000): s = 'text'*100 + 'text'*100 + ... # всего 10 раз >>> timeit(t4, number=10000) 12.795130728000004 >>> timeit(t5, number=10000) 2.642637542999182 >>> timeit(t6, number=10000) 0.2184546610005782 Вот, уже другой разговор, сразу видна разница, в среднем в 6 раз. Но погодите, почему последний тест t6() по скорости такой же как и t3()? Ведь строки теперь в 100 раз длиннее! Это вопросы оптимизации кода, какие простые изменения ускоряют или замедляют выполнение программы. Мы столкнулись с примером обхода обращения к переменной. Например, именно так работает директива #define в С++, во время компиляции подставляя значение переменной вместо ссылки на неё. В Python это тоже работает, но часто ли вы сможете встретить такой способ работы со строками? К сожалению, способ почти только теоретический. В целом, тесты показали то, что мы хотели. Делаем выводы самостоятельно. Полный листинг 🌍 #tricks

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Пронајдени 30 слични објави

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NEA Singapore

@NEASingapore · Post #803 · 31.03.2024 г., 07:19

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Over 5,000 dengue cases were reported in the first quarter of 2024, more than double the 2,360 cases reported in the same period last year. Since the start of 2024, the weekly number of reported dengue cases has remained high, at above 300. There have also been 7 dengue deaths this year. Read on at https://go.gov.sg/dengue-outlook-2024 Dengue risk factors present – high Aedes mosquito population, low population immunity against the Dengue virus – may lead to a surge in dengue cases. Collective responsibility and action are critical. Here’s what you can do to prevent mosquito bites and break dengue transmission: S-A-W (especially if you are diagnosed with or suspected to be infected with dengue) ✔️Spray insecticide in dark corners around the house ✔️Apply insect repellent regularly ✔️Wear long-sleeve tops and long pants Let’s practise these #BLOCK steps at least once a week, to protect ourselves and our families from dengue. B-L-O-C-K ✔️Break up hardened soil ✔️Lift and empty flowerpot plates ✔️Overturn pails and wipe their rims ✔️Change water in vases ✔️Keep roof gutters clear and place BTI insecticide inside 📲Download the myENV app to receive alerts on high Aedes mosquito populations near you, or visit https://go.gov.sg/dengue-high-risk Areas with higher Aedes aegypti mosquito population have a higher risk of dengue and Zika transmission: https://www.nea.gov.sg/dengue-zika/Aedes

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NEA Singapore

@NEASingapore · Post #629 · 31.08.2023 г., 23:01

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#SGDengueUpdate 198 new dengue cases and 35 active dengue clusters were reported in the week ending 26 Aug 2023. Let’s actively do the #BLOCK steps: https://go.gov.sg/mozzieproof

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#sgdengueupdate#block
NEA Singapore

@NEASingapore · Post #626 · 24.08.2023 г., 10:06

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#SGDengueUpdate 193 new dengue cases and 41 active dengue clusters were reported in the week ending 19 Aug 2023. Let’s actively do the #BLOCK steps: https://go.gov.sg/mozzieproof

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#sgdengueupdate#block
NEA Singapore

@NEASingapore · Post #624 · 17.08.2023 г., 10:14

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#SGDengueUpdate 197 new dengue cases and 37 active dengue clusters were reported in the week ending 12 Aug 2023. No new Zika case was reported last week. Let’s actively do the #BLOCK steps: https://go.gov.sg/mozzieproof

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#sgdengueupdate#block
NEA Singapore

@NEASingapore · Post #604 · 27.07.2023 г., 09:38

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#SGDengueUpdate 202 new dengue cases and 41 active dengue clusters were reported in the week ending 22 Jul 2023. 1 new Zika case was reported. Let’s continue to actively do the #BLOCK steps: https://go.gov.sg/mozzieproof

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#sgdengueupdate#block
KOMPYUTER AKADEMIYASI

@Kompyuter_akademiyasi · Post #5566 · 01.11.2023 г., 14:56

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#youtube#block 📹 YouTube butun dunyo bo‘ylab foydalanuvchilar reklama blokerlaridan foydalansalar, video ko‘rishlarini taqiqlashni boshladi. ➖@texnologiyait➖

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NEA Singapore

@NEASingapore · Post #694 · 26.10.2023 г., 09:00

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#SGDengueUpdate 208 new dengue cases and 51 active dengue clusters were reported in the week ending 21 Oct 2023. #DidYouKnow that individuals infected with dengue are advised to avoid further mosquito bites, to prevent passing on the virus to mosquitoes and other people in the neighbourhood? They can do so by practising S-A-W. To protect ourselves and our families from dengue and Zika, it is critical that we all play our part and do the #BLOCK steps at least once a week. ⚠️ Urgent action from all is critical to prevent a surge in dengue cases at year-end. Areas with higher Aedes aegypti mosquito population have a higher risk of dengue and Zika transmission: www.nea.gov.sg/dengue-zika/Aedes

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#sgdengueupdate#didyouknow#block
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