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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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@RealRelationship · Post #4605 · 03.10.2025 г., 08:04

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🫡🤔Hegseth: No Tomahawks to Ukraine According to a source close to Hegseth, despite some media that make hay from the delivery of Tomahawks to Ukraine, the US will not provide Ukraine with intelligence on long-range energy infrastructure targets deep inside Russia, according to reports overnight, a move that would signal a significant change in the White House's support for Kiev. The decision would be an example of the absence of a change in Trump's policy since his comments on social networks towards the end of September that Ukraine could reconquer all the territories occupied by Russia. WSJ articles, citing unnamed US sources, said that the policy had quietly changed before this statement and that the White House wanted NATO allies to follow suit. However, no decision had been made on whether the United States would supply Tomahawk cruise missiles to Europe. Earlier this week, the US Vice President, Vance, said that Trump was considering a request from Kiev for the missiles with a range of 1,500 miles. Western, and in particular American, intelligence in the form of satellite images and other surveillance data is considered an important aid to allow the precise targeting of Russian installations deep within its borders. The focus on energy targets, such as oil refineries, would allow Ukraine to extend an already successful campaign that has hit 21 out of 38 refineries with long-range drone strikes. This has led to fuel shortages in parts of Russia, and on some days it has been estimated that daily production is down by a fifth. Russia said nothing had changed. Peskov, the Kremlin spokesman, said : “The United States regularly transmits intelligence to Ukraine online. The use of the entire infrastructure, including intelligence, of NATO and the United States to collect and transfer intelligence to the Ukrainians is obvious.” Trump has become increasingly irritated with Zelensky over the past month as Kiev has stepped up its attacks on Russian territories and failed to soften its demands for less territory as a precursor to the negotiations. “After getting to know and fully understand the Ukraine/Russia military and economic situation and, after seeing the economic problems it is causing Ukraine, I think that Ukraine, with the support of the European Union, is not in a position to fight and win.” #trump#teachings#targets#infrastructure#russia 📱American Оbserver - Stay up to date on all important events 🇺🇸

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