Going asynchronous: from Flask to Twisted Klein. , Tobias Oberstein Introduction to Twisted Klein, which is like Flask, but allows running asynchronous code.
Preface This post (part 1/2) is an introduction/tutorial for Twisted Klein and assumes basic knowledge of Python, Flask and Twisted. If you don't know Twisted, here is a good introduction. Move on to part 2: Mixing Web and WAMP code with Twisted Klein Related: Twisted Mixing: A talk by Laurens Van Houtven at PyCon 2014Crochet: A library for running Twisted code from blocking/threaded applications Introduction Flask is a Python microframework for the Web.
However, there is one thing that is limiting: I cannot use non-blocking, asynchronous code in my request handlers Why is that? Flask, like Django, Pyramid and others, are based on WSGI, an API standard for connecting Python Web frameworks to Web servers. WSGI was designed for the old fashioned, threaded/pre-forked Web servers (think Apache). Why is that limiting? Can we fix it? The Synchronous World pip install flask requests. Real Python: Promotion Code. PyCon US 2014. Isso – a commenting server similar to Disqus. Peps: fb24c80e9afb. Overview — NetworkX 1.6 documentation. As Piël » Socket Benchmark of Asynchronous Servers in Python. There has already been written a lot on the C10K problem and it is known that the only viable option to handle LOTS of concurrent connections is to handle them asynchronously. This also shows that for massively concurrent problems, such as lots of parallel comet connections, the GIL in Python is a non-issue as we handle the concurrent connections in a single thread.
In this post i am going to look at a selection of asynchronous servers implemented in Python. Asynchronous Server Specs Since Python is really rich with (asynchronous) frameworks, I collected a few and looked at the following features: What License does the framework have? This gave me the following table. This is quite a list and i probably still missed a few. Orbited / Twisted (callbacks)Tornado (async)Dieselweb (generator)Eventlet (greenlet)Concurrence (stackless)Circuits (async)Gevent (greenlet)Cogen (generator) To quickly summarize this list; Twisted has been the de-facto standard to async programming with Python.
Gnome. Framework. Yaml. [j-mad] Django-countries ,l’app garantie sans cowboy ni rodéo. djangoApp de mai 1 sur 2. Il va falloir que je me surveille .. parce qu’encore une fois je publie ma django app du mois un peu en retard. Pas grand chose, juste 4 jours.. Mais ça commence comme ça et après on finit par ne plus tenir de rythme du tout. Du coup, pour marquer, le coup, je publierais deux django app du mois de mai, même si je les publie en juin. Et pour commencer, django-countries. C’est d’ailleurs assez rigolo parce que je parlais il y a peu de moyen de gérer les pays, avec une liste de choix existantes, etc.. et op, je tombe sur django-countries. Vous trouverez django-countries soit sur sa page pypi soit sur sa page bitbucket. Pour l’installation, vous avez les trois moyens désormais classique : un easy_install un pip install un bon vieux hg clone La doc elle se limite à : la page pypi le readme du repository Sachant que dans les deux cas, le contenu est le même. L’app rajoute tout simplement un nouveau type de field, le CountryField.
Et oui, comme dans les vrais sites et tout quoi. Coding styles comparison in the Open Source world. While looking for existing C coding standards I discovered that the GNU and Linux projects officially suggest very different styles. Inside the Linux kernel documentation, Linus Torvalds goes so far as to mock GNU coding standards: First off, I’d suggest printing out a copy of the GNU coding standards, and NOT read it. Burn them, it’s a great symbolic gesture. At this point I wanted to understand the difference between the coding styles of established open source projects. When I say “styles” I mean mainly the source code appearance, and the standards that help to read and maintain the code. Many stylistic aspects can’t be compared directly because they are different languages, but it was interesting to map some of them, for example indentation and maximum line length: About indentation, the styles describe differently the indentation of function declarations from the indentation of branches (thanks to TaQ for the Ruby suggestions and to JoeT for the correction on the Java example):