回顾一下在第3部分中我们实现了投票应用的基本框架结构，但是并没有实现真正的投票表单和处理，以及结果显示等功能， […]

We will see how to deploy a Django project with nginx and gunicorn. It was easier for me to understand nginx and gunicorn on development machine and then move to a publicly accessible server. So, we will cover this post in a similar sequence: On development machine Use django's runserver to serve the site. Stop runserver and start using gunicorn instead. Add nginx to this configuration. On server Deploy the project on a publicly accessible server using same stack. Use runserver We will use a minimal project with two apps and few static files. You can view this project at github. Project structure: |-- manage.py |-- other_app | |-- __init__.py | |-- models.py | |-- static | | `-- other_app | | `-- styles.css | |-- tests.py | |-- urls.py | `-- views.py |-- project_static | `-- base.css |-- requirements.txt |-- some_app | |-- __init__.py | |-- models.py | |-- static | | `-- some_app | | `-- styles.css | |-- tests.py | |-- urls.py | `-- views.py |-- templates | |-- other_app | | `-- home.html | `-- some_app | `-- home.html |-- test.db `-- test_project |-- __init__.py |-- settings.py |-- test_settings.py |-- urls.py `-- wsgi.py This project was ...

在本节中, 我们将介绍最佳的本地开发环境设置 1. 在开发和部署服务器中使用相同的数据库 可能有些开发者喜欢在本地开发Django程序时, 使用SqLite3数据库, 而在部署时使用PostgreSQL数据库(或任何不同于SqLite3的数据库). 但这一做法应当避免, 因为我们是希望不同的数据库表现的一致, 这显然是不现实的. 以下是一些我们使用不同数据库进行开发和部署时遇到的问题: Fixtures不是解决方法 或许你会想, 我们为何不能用fixtures来弥补不同数据库的不同呢? 是的, fixtures能用于创建简单的手写的测试数据, 它能在开发时填充进许多假的数据, 尤其是在开发初期阶段. 但是, fixtures对于从一个数据库到另一个未知数据库的大数据迁移而言, 并不是一个可靠地工具. 它本身也不是为了这一目的而设计的, 我们不应该将创建基本数据和数据迁移的用法混淆. 无法本地测试部署后数据 当你的本地数据库和部署数据库不同时, 你无法创建一个和部署服务器完全一样的拷贝进行测试. 当然你可能会觉得使用dump将数据完全拷贝出来放到本地数据库中测试, 但是这也无法保证导出和导入后的数据是完全一样的. 不同数据库拥有不同的数据类型 请牢记, 不同的数据库处理数据的类型是不同的! Django的ORM试图统一这些不同, 但毕竟所能实现的效果是有限的. 比如, 在使用SqLite3作为测试数据库, 而使用PostgreSQL作为部署数据库时, 由于SqLite3是动态, 弱类型数据库, 而PostgreSQL则是强类型数据库, 虽然程序在测试服务器上运行正常, 但最终可能导致在部署服务器上出现问题. 2. 使用Pip和Virtualenv 如果你还没有使用Pip和Virtualenv, 那么, 我们强烈推荐你现在就开始熟悉并使用Pip和Virtualenv. Pip和Virtuaenv是Django项目的标准配置, 并且大多数开发者依赖这两个工具. Pip是从Python Package Index下载Python模块的工具, 更是管理和安装Python模块的不二选择. 它有点像easy_install, 但具有更多的功能, 其中最重要的就是对于Virtualenv的支持 Virtualenv是创建独立的Python开发环境, 管理模块依赖性的工具. 当我们同时开发多个项目时, 且这些项目使用的库或模块都有所不同时, 它可以帮助我们轻松的在这些独立开发环境质检切换. 当然为了方便使用Virtualenv, 我们可以借助virtualenvwrapper. virtualenvwrapper为我们提供了诸多命令, 方便我们使用Virtualenv 3. 使用Pip安装Django和其他依赖库 Django官网提供了多种安装Django的方式, 但我们推荐使用pip来安装Django和其他项目依赖模块. 简单而言, 每个Django项目都需要一个requirements文本文件, 其中罗列了所有本项目中使用到的Python模块, 每条信息包括了模块的名字和版本号. 我们就使用pip将这些requirements安装到项目的virtualenv中, 具体的说明我们会在将来谈到requirements时做一个详细的介绍. 4. 使用版本控制系统 版本控制系统又叫源代码管理系通, 在进行任何语言的编程时, 你都应当使用版本控制系统来管理跟踪你的源代码. 如果你不了解的话, 可以搜索一下, 应该能找到各版本控制系统的详细比较. 在所有的版本管理系统中, 我们推荐使用git. 因为第一, git似乎是现在最为流行的版本控制系统, 第二它可以方便的建立和合并分支. 在使用版本控制软件的同时, 我们推荐使用GitHub或Bitbucket作为在线的源代码仓库, 用于备份源代码仓库. 5. 试着使用Vagrant Vagrant是一个用于创建, 设置和管理开发环境的工具. Vagrant借助VirtualBox等虚拟化工具, 可以轻松的创建我们需要的虚拟机开发环境. 例如, 我们的开发环境是OS X, 而部署环境是Ubuntu时, 我们就可以使用Vagrant创建一个Ubuntu虚拟机, 并在其中配置好开发环境. 详细的介绍, 我们会在将来讲到开发环境时再谈.

Some time ago I've released django-content-bbcode - a BBCode alike tag parser. In this article I'll show some example of usage for such parser - from simple search and replace to more complex using database to get the response.

The upcoming Django 1.7 has many interesting and welcomed changes. One of them is an update to how applications are loaded. The relase notes also mention potential problems with these changes. I ran into RuntimeError: App registry isn't ready yet while using the self-contained tests approach, but the fix is as simple as mentioned in the docs. # Django 1.7 try: import django django.setup() except AttributeError: pass

Vous êtes djangonautes ? Et vous n’avez pas encore acheté votre billet pour DjangoCon Europe ? Alors peut-être que vous ne le saviez pas. Après tout, même si on a essayé de faire un maximum de com sur le sujet, on n’en fait jamais assez et il est fort possible que vous soyez passé à coté. Donc, je vous refais un petit topo. 3 jours de confs du 13 au 15 mai et 2 jours de sprint le 16 et 17 mai. Et tout cela en France, donc facile au niveau transport, il vous suffit de prendre un TGV. Mais surtout, surtout, ce ne sont pas trois jours de confs dans une simple salle de conf, aussi belle soit-elle. Non, ce sont trois jours de confs (et 2 jours de sprint) dans une île. Oui, dans une ILE. L’île des embiez pour être exact, une petite île qui se trouve dans le Var qui appartient à la famille Ricard. Imaginez donc la scéne. Vous sortez de votre TGV à Toulon, vous prenez un bus et vous arrivez sur un port, le port du Busc. Et la vous prenez un petit ferry et vous voguez, le doux soleil de méditerranée vous ...

Django模板语言中的url命令可通过使用命名空间语法防止url名称的重复，例如： [crayon-5346 […]

It’s been a few years since we last updated our website, and we gave it a whole new look! With the new site, it’s easy to see just what services we offer, and our processes for bringing our client’s ideas to life. The new layout allows for more in-depth reviews of our projects, and also highlights our talented and growing team. We also wanted to share more information on our commitment to the open source community and social good. And the updated structure makes finding out about events and reading our ever-popular blog posts simple. The new design utilizes a responsive grid structure and a refined typographic sensibility. Wrap this all up with our new branding—adding a bold blue to our green/grey—and you get a polished and and informative new site that reflects what Caktus does best. We hope you find the new site more intuitive, user-friendly and as easy-on-the-eyes as we do!

See what it takes to use the new migrations system that has been integrated into Django 1.7. This video walks you through how to create migrations, and run them. Along with a few other key points you might want to know.Watch Now...

For PyCon 2014, we’ve been working for the past few months on Duckling, an app to make it easier to find and join casual group outings. Our favorite part of PyCon is meeting up with fellow Pythonistas, but without someone rounding everyone up and sorting the logistics, we’ve found it difficult to figure who’s going where and when. Our answer to this age-old conference conundrum is Duckling!  Duckling, made for conferences, lets you find, join, and create outings to local restaurants, bars, or other entertainment venues. You can see who’s going, when, and where they’re meeting up to leave. It’s hooked up to Yelp, so you can look at reviews before heading out. And of course, it is written in Django too!  Lots of options to keep up to date on all outings at PyCon: follow @ducklingquacks, find our Duckling sign in the lobby, or come visit our booth to see a map that shows where everyone is headed. Also, our booth will have a giant duck. Why? Because look how happy it makes people!

Version 2.3.0 of my comics aggregator is now released. As always, dependencies have been updated, including the routine Django upgrade from Django 1.5 to 1.6, just in time for the upcoming 1.7 release. The largest change this time around is the move from Bootstrap 2 to 3, which includes a refreshed, flatter design and lots of tweaking to make Comics both look good and work nicely on mobile devices, something it didn’t use to do. The dependency overview at requires.io has been a great motivation for doing some maintenance work on Comics. The only dependency left outdated is django-registration, as 1.0 moves to class-based views, which requires some larger changes to my customizations. Thus, the upgrade of django-registration has been deferred together with the related upgrade of my vendorized copy of django-invitation. Most, if not all, of the other dependencies seems to support Python 3 now, though some lack the right Trove classifiers in their PyPI registration, so they are not correctly labeled by requires.io. I found an open pull request for cssmin and a recent commit for django-compressor adding the missing Trove classifiers. I’ve also done my part to improve the Python 3 metadata by sending a pull request ...

Hi everyone. This is just a small announcement today to let everyone know that we decided to change our publication schedule. From now on we are going to try to release 2 blog posts every week, one on wednesday and one on friday. This wednesday will be the day we release Ls4c. There will be  a link to the repository and documentation as well as a small tutorial on how to create a multilingual webshop using Ls4C in less than an thirthy minutes. This friday we will feature the next episode of our Django babbler tutorial series: Custom users using Django 1.6. In the mean time, have a great monday everyone!

gaqzi 最近的开源项目 django-emoji 可心让你的django APP 在网站上显示流行的 em […]

App enlight, a Polish startup known as errormator in the past is a application-service that logs and aggregates you application health. Like for example Sentry can log exceptions and logs (like from logging module) then App Enlight does much more by hooking to the internals of the application - you will get executed SQLs, template rendering time, slow responses and more. So let us take a closer look on current app enlight features...

New to Python and/or conferences and attending the upcoming PyCon 2014 in Montreal, Canada? Or is this your first conference? Or perhaps your first conference longer than a weekend? Hoping to get the most out of joining thousands of Python enthusiasts? No worries! This guide will aid you in attending one of the best technical conferences on the planet. Even though I'm not attending on account of various reasons including finances, work, and surgery, I'm going to share how to get through the whole event in good shape. I'm also going to share some great tricks to optimize the event. Basics Take at least one shower per day. Please. Bring something to take notes. A paper notebook, laptop, or tablet. Anything! If you are looking for work, bring business cards. Seriously. At every meal (breakfast, lunch, dinner) make a point of sitting with or going out with different people. Introduce yourself. Make new friends and learn new things! If you can't make it to a talk, don't stress out. They are recorded and will be available later on http://www.pyvideo.org. Act Professionally (see next section) Be Professional PyCon is a professional event. Sure, lots of people are in t-shirts and are ...

For a long time, one of my fellow core developers on the Django project has had an email signature which contains the following: "I disapprove of what you say, but I will defend to the death your right to say it." -- Evelyn Beatrice Hall (summarising Voltaire) My perception of the reaction and noise around Brendan Eich's appointment (and subsequent resignation) as CEO of Mozilla has been that many (though by no means all) in the tech community haven't held true to this (though I think many would claim that they have). I'm afraid I can't be silent on this issue any more, and I have to speak out. You are more than welcome to disagree with me (as I'm sure many of you will!) but please at least hear me out. I was pushed further by a comment on a blog post (both of which have since disappeared) in which the author said that he would be very scared to speak out if he opposed gay marriage, and that fear is not the tactic we should be using to discourage this view. I agree completely with that sentiment. The current temperature in the programming community feels extremely hostile to ...

There are many ways to optimize PNG files, but one optimization which is commonly overlooked involves the PNG's transparent background. If you’ve chosen to use PNGs instead of a more compact format like JPG, mainly for the PNG's support of a transparent background (alpha channel), read on and see how dynamic underlays can reduce your file size by as much as 1:5. Graphic designers of sites and apps sometimes wish to display clipped photos on top of a certain background. A common example is a news site that shows a head shot of the author, or a figure mentioned in the article. Typically, the images are clipped using photo editing software like Photoshop, and then they can then be placed above background colors, patterns and between text paragraphs. The issue is that the image may be placed in different contexts, and in each context the background could have a different color. The need arises to give the image a transparent background, and this requires a file format that supports transparency (alpha channel). The format typically chosen is PNG, and this can increase file size substantially. How it's usually done - image saved as transparent PNG For example, the following photo ...

While Audrey Roy Greenfeld and I were contemplating our next Two Scoops Press book topic, it came down to a decision between Pyramid, Flask, and mythical creatures. Inspired by Django's magical flying pony, Pyramid's scary alien dude, and even the idea of a magical Flask pouring out wonderful projects, we've decided to go with mythical creatures. Specifically, we're writing about goblins, hence the title of this blog post. What that means is that the next book we publish will be fantasy. Going forward all the books we write will be fiction. If we ever write a new Two Scoops of Django book, it will be a fantasy about a magical flying pony who eats ice cream. That way we'll confuse the already muddled Amazon.com search requests for 'Django' even more. Since this is a technical blog, I'll be moving my fiction writing based articles to my author blog at dannygreenfeld.com.

Providing csv files to people is annoying, but writing a custom mixin for use with your views can make it super easy. Often times we have to use a custom function, of some sort, and rejigger around how our views work to get a csv file, then set header information, and finally return a response. There is a Better Way Below is a custom mixin you can write, or use, to return a csv file based on a list of lists. class CSVResponseMixin(object): csv_filename = 'csvfile.csv' def get_csv_filename(self): return self.csv_filename def render_to_csv(self, data): response = HttpResponse(content_type='text/csv') cd = 'attachment; filename="{0}"'.format(self.get_csv_filename()) response['Content-Disposition'] = cd writer = csv.writer(response) for row in data: writer.writerow(row) return response The first few lines of code are simple. We are declaring the mixin, setting the filename, and returning the filename based on a method on the mixin. That leaves us with the render_to_csv method which takes a lsit of lists, and gives us a downloadable file. Line by Line Explanation response = HttpResponse(content_type='text/csv') We are creating a Django HttpResponse object which django returns, and we are setting the content type to a csv file so the browser knows what it is. response['Content-Disposition'] = 'attachment; filename="{0}"'.format(self.get_csv_filename()) We are ...

看到这个标题, 你很有可能会跳过这篇文章. 但我们认为只需要在编码时稍加注意, 良好的编码风格会影响颇深. 1. 代码可阅读性的重要性 代码写出来之后, 更多的时间是被阅读. 一段代码可能只用了几分钟就被写了出来, 几十分钟或几小时用来测试debug, 但可能一年或 几十年后都不会再被人修改. 恰恰, 当你或者别人一年或几十年后再阅读时, 一贯简洁的编码风格显得尤为重要. 它使得你不用去猜 想代码的不连续性, 使得大项目更容易维护, 使得小项目也更容易扩展. 那么, 怎么才算是良好的编码风格呢? 避免过度缩写的变量名 清晰的写出function传入参数(argument)的名字 为class和method写注释 重构代码: 将重复的代码提取出来, 写成function或method 保持function和method简短: 一个简单的规则是, 阅读一个function或method时, 不需要翻页 这样, 当重新接触长时间没有查看的代码时, 你会发现阅读和理解代码的时间会大大缩短. 例如, 当你读到一个名为 blance_sheet_decrease的变量时, 是不是比bsd或b_s_d这样的变量名更容易理解? 类似这样的缩写名, 虽然能在编写代码是为你节 省几秒钟, 但当重新阅读时, 可能耗费你几个小时. 因此这种缩写是不值得的! 2. PEP8 PPE 8是Python官方的代码风格指导. 我们建议你详细的阅读并使用这些规范: http://www.python.org/dev/peps/pep-0008/ 需要注意的是, PEP8只适用于新的项目, 如果将PEP8带入到已有项目时, 在有代码风格冲突时, 应保持原有规范, 以防发生混乱. 举些例子, PEP 8中定义的代码规范有: 每一等级的缩进使用4个空格 在最高级function和class前空两行 class中定义的method, 应该与前面的代码空一行 关于每行字符数限制 PEP8中, 规定了每行字符数的限制是79. 因为这是绝大多数编辑器和开发团队都能支持的字符数. 但PEP8中也有条款, 可将该限制扩展到99个字符数. 我们的理解是, 当该项目是开源时, 应尽量 将字符数控制在每行79个, 而当项目是闭源时, 则可以扩大到79个字符数. 3. 关于import 我们建议import按以下顺序排列: Python标准库 Django自带库 第三方App库 项目中App库 例如: # Python标准库 from __future__ import absolute_import from math import sqrt from os.path import abspath # Django自带库 from django.db import models from django.utils.translation import ugettext_lazy as _ # 第三方App库 from django_extensions.db.models import TimeStampedModel # 项目中App库 from .models import BananaSplit 使用明确指明的相对路径引用 当在写代码时, 应当时刻注意所写的代码应当能方便的移动, 重命名和升级. 在Python中, 使用明确指明的相对路径引用 (explicit relative import), 降低了模块之间的耦合性, 为我们带来了以上三个优点. 以上代码中的"from django_extensions.db.models import TimeStampedModel"便是一个很好的例子. 避免使用* 大多数情况下, 为了避免引起不可预料的混乱, 我们都不应该使用import *. 4. 其他 虽然在PEP8中没有明确指明, 但在实践中, 因尽量使用下划线"_", 而不是横杠"-", 因为下划线对于大多数IDE和文本编辑器都很友好. 但在URl中, 两者没有差别.

I’ve recently been tweaking my server setup for a Django 1.3 web site with the goal of making it a bit faster. Of course, there is a lot of speed to gain by improving e.g. the number of database queries needed to render a web page, but the server setup also has an effect on the web site performance. This is a log of my findings. All measurements have been done using the ab tool from Apache using the arguments -n 200 -c 20, which means that each case have been tested with 20 concurrent requests up to 200 requests in total. The tests was run from another machine than the web server, with around 45ms RTT to the server. This is not a scientific measurement, but good enough to let me quickly test my assumptions on what increases or decreases performance. The Django app isn’t particularly optimized in itself, so I don’t care much about the low number of requests per second (req/s) that it manages to process. The main point here is the relative improvement with each change to the server setup. The baseline setup is a Linode 1024 VPS (Referral link: I get USD 20 off my ...

Version 2.2.0 of my comics aggregator is now released. It features a general upgrade of dependencies, including the move from Django 1.4 to Django 1.5, and a lot of updates to comic crawlers. The Django upgrade was completed months ago and it’s been running my Comics instance since, so it’s about time to get it released before Django 1.6 arrives in a month or two. Regarding the crawler updates, it’s a bit sad to see that many of the crawlers have been broken for months without me or anybody else noticing, but it’s hard to catch some content lacking in the middle of a firehose of similar content. I guess I’ll have to make it a monthly task to look through the crawler status page of my Comics instance and do patch releases with updated crawlers. Check out the project docs for more information about Comics and this release in particular.

My tutorial about creating ember.js applications with Django got updated to the latest ember.js version and the source code got published on github. I'm planning to write more about this framework soon, as now I'm spending a lot of time working with ember and Django, django-rest-framework and other interesting libraries. Aside of that I still have some topics on my ToDo list - Facebook apps related packages (future; when they get published), more Python + electronics tutorials, and Django/Python related (like checking Cherokee server or testing AppEnlight). What you find most interesting?

Although this is certainly not the usual use case for a Django site, I am deploying a new site that will be used by several programs at the school where I work. Each program will have its own specific Django settings file with its own values (for example, the database connection info) but for the most part the sites share a base settings_production.py file. Here is a sample of this file: from mysite.settings import * DEBUG = False TEMPLATE_DEBUG = DEBUG ALLOWED_HOSTS.append('.university.edu') INSTALLED_APPS.append( 'websso' ) MIDDLEWARE_CLASSES.append( 'django.contrib.auth.middleware.RemoteUserMiddleware' ) AUTHENTICATION_BACKENDS.append( 'websso.backends.RegistryRemoteUserBackend' ) DATABASES = { 'default': { 'ENGINE': 'django.db.backends.postgresql_psycopg2', 'NAME': os.environ.get('MYSITE_DB_NAME'), 'USER': os.environ.get('MYSITE_DB_USER'), 'PASSWORD': os.environ.get('MYSITE_DB_PASSWORD'), 'HOST': os.environ.get('MYSITE_DB_HOST'), 'PORT': '5432', } } As you can see, we get the database connection values from the environment. I am using Apache (with mod_proxy_uwsgi) and uwsgi in emperor mode to run the site, and each site has a uwsgi ini file that actually sets all the relevant per-site settings via the env configuration option. This was quite easy to set up, and this is an example uwsgi ini file: [uwsgi] chdir=/srv/myvirtualenv/mysite module=mysite.wsgi:application max-requests=5000 socket=127.0.0.1:3032 logto=/tmp/uwsgi-example.log env = DJANGO_SETTINGS_MODULE=mysite.settings_production env = MYSITE_DB_NAME=mysite_dbname env = MYSITE_DB_USER=mysite_username env = MYSITE_DB_PASSWORD=abc123 env = MYSITE_DB_HOST=mysite-dbname.hostname.us-east-1.rds.amazonaws.com So far so good -- ...

Caleb Smith, Caktus developer, awarding the third place prize to TheRightFit creators Bipasa Chattopadhyay, Ping Fu, and Sarah Andrabi. Many congratulations to the PearlHacks third place winners who won Sphero Balls! The team from UNC’s Computer Science department created TheRightFit, an Android app that helps shoppers know what sizes will fit them and their families among various brands. Their prize of Sphero Balls, programmable balls that can interact and play games via smart phones, was presented by Caktus developer and Pearl Hacks mentor Caleb Smith as part of our sponsorship. PearlHacks, held at UNC-Chapel Hill, is a conference designed to encourage female high school and college programmers from the NC and VA area. Also, we’re deeply proud of our intern, Annie Daniel (UNC School of Journalism), who was part of the first place team for their application, The Culture of Yes. Excellent job, Annie! This is what Annie had to say about her team's first place project: The Culture of Yes was a web app that's meant to broaden the conversation on sexual assault on college campuses. We chose a flagship university from each of the 50 states, created a json file that summarized that university (population, male/female ratio, % ...