@djangoproject · Post #529 · 19.12.2017 г., 22:08
http://www.djangocrew.com/blog/how-manage-concurrency-django-models/ In this Post we are going to present two approaches for managing #concurrency in #Django models.
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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
Пребарај: #concurrency
@djangoproject · Post #529 · 19.12.2017 г., 22:08
http://www.djangocrew.com/blog/how-manage-concurrency-django-models/ In this Post we are going to present two approaches for managing #concurrency in #Django models.
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@djangoproject · Post #95 · 11.07.2016 г., 12:14
https://docs.python.org/3/library/asyncio-dev.html#asyncio-multithreading 18.5.9.3. #Concurrency and #multithreading An event loop runs in a thread and executes all callbacks and tasks in the same thread. While a task is running in the event loop, no other task is running in the same thread. But when the task uses yield from, the task is suspended and the event loop executes the next task. To schedule a callback from a different thread, the BaseEventLoop.call_soon_threadsafe() method should be used. Example: loop.call_soon_threadsafe(callback, *args) Most asyncio objects are not thread safe. You should only worry if you access objects outside the event loop. For example, to cancel a future, don’t call directly its Future.cancel() method, but: loop.call_soon_threadsafe(fut.cancel) To handle signals and to execute subprocesses, the event loop must be run in the main thread. To schedule a coroutine object from a different thread, the run_coroutine_threadsafe() function should be used. It returns a concurrent.futures.Future to access the result: future = asyncio.run_coroutine_threadsafe(coro_func(), loop) result = future.result(timeout) # Wait for the result with a timeout The BaseEventLoop.run_in_executor() method can be used with a thread pool executor to execute a callback in different thread to not block the thread of the event loop. See also The Synchronization primitives section describes ways to synchronize tasks. The Subprocess and threads section lists asyncio limitations to run subprocesses from different threads.
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@djangoproject · Post #195 · 08.11.2016 г., 03:18
http://stackoverflow.com/questions/29269370/how-to-properly-create-and-run-concurrent-tasks-using-pythons-asyncio-module In the case of trying to concurrently run two looping Tasks, I've noticed that unless the Task has an internal await expression, it will get stuck in the while loop, effectively blocking other tasks from running (much like a normal while loop). However, as soon the Tasks have to wait--even for just a fraction of a second--they seem to run concurrently without an issue. Thus, the await statements seem to provide the event loop with a foothold for switching back and forth between the tasks, giving the effect of #concurrency. Example output with internal await: running async test ...#boo 0 ...#baa 0 ...boo 1 ...baa 1 ...boo 2 ...baa 2
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@djangoproject · Post #157 · 06.09.2016 г., 19:55
https://docs.python.org/2/library/multiprocessing.html #multiprocessing is a package that supports spawning processes using an #API similar to the #threading module. The multiprocessing package offers both local and remote #concurrency, effectively side-stepping the Global Interpreter Lock by using subprocesses instead of #threads. Due to this, the multiprocessing module allows the programmer to fully leverage multiple processors on a given machine. It runs on both Unix and Windows.
@djangoproject · Post #106 · 30.07.2016 г., 21:03
top prev next #ZeroMQ (also known as ØMQ, 0MQ, or #zmq) looks like an embeddable networking #library but acts like a #concurrency framework. It gives you sockets that carry atomic messages across various transports like in-process, inter-process, TCP, and multicast. You can connect sockets N-to-N with patterns like fan-out, pub-sub, task distribution, and request-reply. It's fast enough to be the fabric for clustered products. Its asynchronous I/O model gives you scalable multicore applications, built as asynchronous message-processing tasks. It has a score of language APIs and runs on most operating systems. ZeroMQ is from iMatix and is LGPLv3 open source. http://zguide.zeromq.org/page:all
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@githubtrending · Post #14859 · 24.06.2025 г., 11:30
#typescript#cli#clustering#concurrency#dependency_injection#effect#error_handling#javascript#observability#opentelemetry#platform#schema#typescript#workflows Effect is a powerful TypeScript framework that helps you build reliable and complex applications by managing side effects like logging, network calls, and database operations in a safe and organized way. It uses a core `Effect` type to describe workflows that are lazy, composable, and type-safe, allowing you to handle errors and dependencies explicitly. The framework is modular, with many packages for AI, CLI tools, distributed computing, SQL databases, and more, making it flexible for various needs. Using Effect improves code quality, concurrency handling, and maintainability, helping you write robust TypeScript apps efficiently[1][2][4][5]. https://github.com/Effect-TS/effect
@djangoproject · Post #224 · 07.01.2017 г., 16:53
#AI #automated_testing #automation #asyncio #atexit #button #concurrency #Coroutines #data_mining #dropdownbox #Debian #decorators #django_cms #form #Google #Gym #intelligence #input #lists #machine_learning #map #Metaprogramming #Micro_services #monitoring #Multipart #multi_touch_apps #multiprocessing #Nodes #numerical #OAuth #package #pytest #python #requests #Requests #satellite #scrapy #scikit_learn #SciPy #searching #submit #selectbox #sessions #TensorFlow #text_boxes #text #telegram #Threads #tuples #Universe #urllib #upload
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@djangoproject · Post #298 · 17.04.2017 г., 07:42
#AI#Artificial_Intelligence #aiohttp #API #AWS #asyncio #audio #automated_testing #automation #atexit #BeeWare #button #client #concurrency #cron #Coroutine #data_analysis #data_mining #data_processing #database #Deep_Learning #Debian #decorator #dispatch #django #dropdownbox #Docker #event #Firefox #form #freeze #functool #Generator #GeoDjango #Google #GPU #Gym #learn #Image_processing #intelligence #input #IOT #lambda #lists #machine_learning #Magenta #map #Metaprogramming #Micro_services #mind #monitoring #MongoDB #Mozilla #Multipart #multi_touch_apps #multiprocessing #Nodes #NoSQL #numeric_computation #numerical #NumPy #OAuth #object_serialization #OCR #overloading #package #parallel #pipeline #protocols #PostGIS #pyAudioAnalysis #PyInstaller #PySide #PyTorch #pytest #python #Pyvideo_archives #Qt #Redis #random #request #REST #satellite #scrapy #scikit_learn #SciPy #searching #submit #selectbox #Selenium #serialization #server #session #socket #sound #task #TensorFlow #text_boxes #text #test #telegram #Thread #transport #tuples #Universe #Unix #urllib #upload #Web
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@djangoproject · Post #425 · 28.08.2017 г., 03:37
#AI#Artificial_Intelligence #aiohttp #AngularJS #API #AWS #asyncio #audio #automated_testing #automation #atexit #BeeWare #button #client #concurrency #Coroutine #cron #curl #data_analysis #data_mining #data_processing #database #Deep_Learning #Debian #decorator #dict #dispatch #django #django_cms #dropdownbox #Docker #event #Firefox #form #Generator #GeoDjango #git #Google #GPU #Gym #learn #Image_processing #intelligence #input #IOT #lambda #learn #lists #machine_learning #Magenta #map #Metaprogramming #Micro_services #mind #monitoring #MongoDB #Mozilla #Multipart #multi_touch_apps #multiprocessing #Nodes #NoSQL #numeric_computation #numerical #NumPy #OAuth #object_serialization #OCR #overloading #package #parallel #pipeline #protocols #PostGIS #pyAudioAnalysis #pycon #Pyflakes #PyInstaller #PySide #PyTorch #pytest #python #Pyvideo_archives #Qt #React #Redis #random #request #REST #satellite #scrapy #scikit_learn #SciPy #searching #submit #selectbox #Selenium #serialization #server #socket #task #telegram #TensorFlow #test #text_boxes #text #tuples #unicode #Universe #Unix #urllib #upload #Web
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@djangoproject · Post #513 · 30.11.2017 г., 22:00
#AI#Artificial_Intelligence #AJAX #aiohttp #Anaconda #AngularJS #API #Atom #AWS #asyncio (#Asynchronous) #audio #automated_testing #automation #atexit #BeeWare #Big_Data #bitcoin #blockchain #Bluemix #Brython #button #Celery #client #class #classmethod #concurrency #Coroutine #cron #CSS #curl #data_analysis #data_mining #data_processing #database #Deep_Learning#deep_learning #Debian #decorator #deploy #dict #dispatch #django #django_cms #Django_REST_Framework #dropdownbox #Docker #event #Firefox #Flask #form #functions #Generator #GeoDjango #git #Google #GPU #GUI #Gym #host #HTML #httplib #learn #Image_processing #intelligence #input #Instagram #IOT #iPython #Jupyter #lambda #learn #License #Linux #lists #machine_learning #Magenta #map #Matplotlib #Metaprogramming #Micro_services #Micropython #mind #monitoring #MongoDB #modules #Mozilla #Multipart #multi_touch_apps #multiprocessing #Nodes #NoSQL #numeric_computation #numerical #NumPy #network #neural_network #OAuth #object_serialization #OCR #overloading #package #parallel #pipeline #protocols #PostGIS #pyAudioAnalysis #pycon #Pyflakes #PyInstaller #PyPI #PyQt #PySide #PyTorch #pytest #python #Pyvideo_archives #Qt #Raspberry_Pi #React #Redis #random #request #Regular_Expressions (#re) #REST #RSS #satellite #scikit_learn #SciPy #scrapy #searching #selectbox #Selenium #serialization #server #sessions #single_responsibility_principle #socket #Spark #str #submit #task #telegram #template #TensorFlow #test #text_boxes #text #tuples #unicode #Universe #Unix #unit_test #urllib #upload #uWSGI #Web #WSGI
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