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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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Mountstorm notes

@mountstorm · Post #653 · 16.07.2023 г., 04:16

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That Eye Blunt Injury The incident of a blunt eye injury during a football game caused me to spend a week alone in the hospital, which led to the discovery of my sense of self. I associate mostly with being a student, as I have always been passionate about learning and developing my knowledge. However, the experience of the injury made me realize that being cautious and aware of my surroundings is also a defining part of my identity. As a student, I am constantly learning and growing, but as someone who has suffered an injury, I am also aware of my vulnerability. This experience has taught me to be more careful and attentive in my day-to-day life, especially when participating in physical activities. Overall, the experience has helped me to redefine my identity and to appreciate the importance of taking care of myself. #yeah

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@mountstorm · Post #170 · 30.05.2022 г., 08:15

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Summer. High School graduates still have the aftertaste of the graduation party and now are preoccupied with summer holidays. While my bro, a 9th grade graduate, can chill for the entire season, he will work on his academic interests and chill. Along with participating in extracurricular summer programs, he will be reading books, however cliche it sounds. Reading a book is like investing in real-estate. As long as you get the right book/estate, you are in a slowly-but-surely growing business. No need for a solid schedule or a measurable goal - how many pages to read daily, specific deadlines - in the beginning. Planning is important, I'd say, when and if there is already a vivid picture of what exactly you need and want to read. I started the process with whatever I had in hand - a fairy-tale collection, a magazine, or a random novel. Bit by bit, it's been getting more clear what genre/author's style is mine and what book to read next. The difference between a "good" book and a "bad" one for me is the first ten pages. Asking for advice on what to read from others is also better done in later stages, I believe. Suggested books are better added to the foundation laid by you. #yeah

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