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

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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Reuters: World

@reutersworldchannel · Post #149508 · 18.10.2021 г., 12:50

October 18, 2021: U.S missionaries, China economy, Robert Durst, India floods, California oil spill October 18, 2021: U.S missionaries, China economy, Robert Durst, India floods, California oil spill 1. A U.S. Christian aid organization said a group of its missionaries had been kidnapped in Haiti, a further sign the Caribbean nation's gangs are growing increasingly brazen amid political and economic crises. 2. China’s economy hit its slowest pace of growth in a year in the third quarter, hurt by power shortages and wobbles in the property sector, highlighting the challenge facing policymakers as they seek to prop up a faltering recovery while reining in the real estate sector. 3. Leaders in the south Indian state of Kerala opened near-overflowing dams on Monday, after at least 22 people died when heavy rains lashed the state over the weekend. 4. Real estate heir Robert Durst, who was sentenced this week to life in prison for murdering a friend in 2000, has COVID and is on a ventilator, his lawyer told the Los Angeles Times. 5. The U.S. Coast Guard boarded a container ship in the Port of Long Beach that dragged its anchor close to a subsea pipeline found to be the source of an oil spill off Orange County, California, it said in a press release. #Haiti #US #Missionaries #China #Economy #RobertDurst #India #floods #Kerala #California #OilSpill #Caribbean #News #Reuters #MorningNews #Headlines Subscribe: http://smarturl.it/reuterssubscribe Reuters brings you the latest business, finance and breaking news video from around the globe. Our reputation for accuracy and impartiality is unparalleled. Get the latest news on: http://reuters.com/ Follow Reuters on Facebook: https://www.facebook.com/Reuters Follow Reuters on Twitter: https://twitter.com/Reuters Follow Reuters on Instagram: https://www.instagram.com/reuters/?hl=en ➖@reutersworldchannel➖

Reuters: World

@reutersworldchannel · Post #149212 · 11.10.2021 г., 14:12

October 11, 2021: Alaska quake, U.S. and Taliban, AstraZeneca, Prince Andrew, California oil spill October 11, 2021: Alaska quake, U.S. and Taliban, AstraZeneca, Prince Andrew, California oil spill 1. An earthquake of magnitude 6.8 struck the Alaska Peninsula region, the European Mediterranean Seismological Centre said. 2. The United States said on Sunday the first face-to-face meeting between senior U.S. and Taliban officials since the hardline group retook power in Afghanistan was "candid and professional" and that the U.S. side reiterated that the Taliban would be judged on their actions, not just their words. 3. AstraZeneca's experimental COVID-19 drug has helped cut the risk of severe disease or death in a late-stage study, the British drug maker said, a boost to its efforts to develop coronavirus medicines beyond vaccines. 4. British police said they would be taking no further action after conducting a review of evidence relating to sex crime allegations against Queen Elizabeth's son, Prince Andrew, and the late U.S. financier Jeffrey Epstein. 5. Beaches in a southern California city that were shut because of an oil spill last week are set to reopen, authorities said in a statement. #Alaska #Earthquake #UnitedStates #Taliban #Afghanistan #AstraZeneca #Covid19 #UnitedKingdom #BritishPolice #PrinceAndrew #Epstein #QueenElizabeth #Headlines #MorningNews #Business #News #Reuters Subscribe: http://smarturl.it/reuterssubscribe Reuters brings you the latest business, finance and breaking news video from around the globe. Our reputation for accuracy and impartiality is unparalleled. Get the latest news on: http://reuters.com/ Follow Reuters on Facebook: https://www.facebook.com/Reuters Follow Reuters on Twitter: https://twitter.com/Reuters Follow Reuters on Instagram: https://www.instagram.com/reuters/?hl=en ➖@reutersworldchannel➖

Reuters: World

@reutersworldchannel · Post #149211 · 11.10.2021 г., 13:51

October 11, 2021: Alaska quake, U.S. and Taliban, AstraZeneca, Prince Andrew, California oil spill October 11, 2021: Alaska quake, U.S. and Taliban, AstraZeneca, Prince Andrew, California oil spill 1. An earthquake of magnitude 6.8 struck the Alaska Peninsula region, the European Mediterranean Seismological Centre said. 2. The United States said on Sunday the first face-to-face meeting between senior U.S. and Taliban officials since the hardline group retook power in Afghanistan was "candid and professional" and that the U.S. side reiterated that the Taliban would be judged on their actions, not just their words. 3. AstraZeneca's experimental COVID-19 drug has helped cut the risk of severe disease or death in a late-stage study, the British drug maker said, a boost to its efforts to develop coronavirus medicines beyond vaccines. 4. British police said they would be taking no further action after conducting a review of evidence relating to sex crime allegations against Queen Elizabeth's son, Prince Andrew, and the late U.S. financier Jeffrey Epstein. 5. Beaches in a southern California city that were shut because of an oil spill last week are set to reopen, authorities said in a statement. #Alaska #Earthquake #UnitedStates #Taliban #Afghanistan #AstraZeneca #Covid19 #UnitedKingdom #BritishPolice #PrinceAndrew #Epstein #QueenElizabeth #Headlines #MorningNews #Business #News #Reuters Subscribe: http://smarturl.it/reuterssubscribe Reuters brings you the latest business, finance and breaking news video from around the globe. Our reputation for accuracy and impartiality is unparalleled. Get the latest news on: http://reuters.com/ Follow Reuters on Facebook: https://www.facebook.com/Reuters Follow Reuters on Twitter: https://twitter.com/Reuters Follow Reuters on Instagram: https://www.instagram.com/reuters/?hl=en ➖@reutersworldchannel➖