Django community: Community blog posts RSS
This page, updated regularly, aggregates Community blog posts from the Django community.
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Tạo môi trường làm việc ảo với virtualenv
Virtualenv là một công cụ để xây dựng môi trường độc lập khi phát triển với Python. Đó là một cách tuyệt vời để nhanh chóng kiểm tra các thư viện mới mà không làm lộn xộn các package có sẵn của bạn hoặc chạy nhiều dự án trên cùng một máy phụ thuộc vào một thư viện đặc biệt nhưng không phải cùng một phiên bản của thư viện đã có. Ví dụ bạn có thể cài đặt phiên bản X của thư viện trong một môi trường và phiên bản Z của cùng một thư viện trong môi trường khác, mà không gây ảnh hưởng đến cái khác. Mỗi môi trường cung cấp thực thi Python riêng của nó và thư mục của site-package (không được chia sẻ giữa các môi trường). Để cài đặt virtualenv, chỉ cần sử dụng easy_install với lệnh sau đây: easy_install virtualenv Một khi virtualenv được cài đặt, bạn có thể sử dụng lệnh virtualenv để tạo ra môi trường ảo. Các lệnh sau đây sẽ tạo ra một môi trường được gọi là "working": virtualenv working Bạn có thể kích hoạt các môi trường bằng cách chạy script kích hoạt nó, nằm … -
EmailInput HTML5 friendly for Django
Suppose you have a Django app with a login where people can only log in with their email address. Then use this widget on your login form: ## The input widget class class EmailInput(forms.widgets.Input): input_type = 'email' def render(self, name, value, attrs=None): if attrs is None: attrs = {} attrs.update(dict(autocorrect='off', autocapitalize='off', spellcheck='false')) return super(EmailInput, self).render(name, value, attrs=attrs) ## Example usage class AuthenticationForm(django.contrib.auth.forms.AuthenticationForm): """override the authentication form because we use the email address as the key to authentication.""" # allows for using email to log in username = forms.CharField(label="Username", max_length=75, widget=EmailInput()) rememberme = forms.BooleanField(label="Remember me", required=False) This input field does some cool stuff in the browser such as automatic validation in the browser as seen in this screenshot here. More importantly it fixes a very annoying problem when surfing on a smartphone or a tablet like the iPad. As I'm about to type "someusername@mozilla.com" it first wants to start capitalized and which might fail the login. Also if the email address contains a word that it wants to correct like ("mozilla" -> "Mozilla") you have to click the little correct tooltip to tell the input is correct in verbatim. Note to Djangonauts who want to use this and have a dual authentication backend that takes both usernames and email addresses, this form will make it impossible to log in as something called "admin" for example. -
EmailInput HTML5 friendly for Django
Suppose you have a Django app with a login where people can only log in with their email address. Then use this widget on your login form: ## The input widget class class EmailInput(forms.widgets.Input): input_type = 'email' def render(self, name, value, attrs=None): if attrs is None: attrs = {} attrs.update(dict(autocorrect='off', autocapitalize='off', spellcheck='false')) return super(EmailInput, self).render(name, value, attrs=attrs) ## Example usage class AuthenticationForm(django.contrib.auth.forms.AuthenticationForm): """override the authentication form because we use the email address as the key to authentication.""" # allows for using email to log in username = forms.CharField(label="Username", max_length=75, widget=EmailInput()) rememberme = forms.BooleanField(label="Remember me", required=False) This input field does some cool stuff in the browser such as automatic validation in the browser as seen in this screenshot here. More importantly it fixes a very annoying problem when surfing on a smartphone or a tablet like the iPad. As I'm about to type "someusername@mozilla.com" it first wants to start capitalized and which might fail the login. Also if the email address contains a word that it wants to correct like ("mozilla" -> "Mozilla") you have to click the little correct tooltip to tell the input is correct in verbatim. Note to Djangonauts who want to use this and have a dual authentication backend that takes both usernames and email addresses, this form will make it impossible to log in as something called "admin" for example. -
The Ultimate Django Tutorial Workshop
That is a big statement to make as a title of a class/workshop blog post. However, in this case I believe I'm fully justified because this is going to be awesome. Here's why:1. The teachers are beyond incredibleIn the course description it says I'm the teacher and I have lab assistants. In retrospect, what I should have said is, "Daniel Greenfeld is organizing a workshop taught by the people he respects and admires".Think I'm kidding? Look at just some of the names of people I've got lined up to participate:Jacob Kaplan-Moss, Benevolent Dictator For Life of DjangoRussell Keith-Magee, President of the Django Software FoundationAudrey RoyJacob BurchKatharine JarmulCorey BertramSandy StrongJonas ObristChristine CheungShimon RuraFollow those links to their bios or talks and you'll see that they are the people speaking at DjangoCon. The general idea is to get the people already speaking at DjangoCon or those who are extremely experienced in it to teach the class.2. The teacher to student ratio is going to be really smallThis is not going to be a room with a few instructors and umpteen students in it. If the class size gets big, I'm going to bring in more teachers. I'll cajole, plead, and do whatever I … -
Gevent, Long-Polling & You
Gevent, Long-Polling & You -
De la web al model
L'scrapping Ahir ja vàrem veure quin era el model de dades i el bé que va sorl per a manipular imatges, així com la utilització de la llibreria requests ens quedava veure una altra part important: com agafar el contingut de la web, parsejar-lo i obtenir-ne la informació que necessitam. Per fer això hi ha diverses utilitats, algunes molt especialitzades com scrappy, i amb més solera és BeautifulSoup. Aquesta llibreria té la qualitat de ser molt permisiva amb l'HTML i hi ha poques planes que no pugui tractar d'una manera o altra. La plana de Meneame té las notícies de portada dins un div anomenat news-summari, així que el primer que farem serà carregar la plana dins una instància de BeautifulSoup i cercar aquestes notícies. page = requests.get('http://www.meneame.net') if page.status_code != 200: print "Ups! pareix que hi ha un petit problema" return page.status_code soup = BeautifulSoup(page.content) noticies = soup.findAll('div', 'news-summary') amb això BS ens haurà donat tots els divs que tenen la classes 'news-summary' amb la qual cosa ja és sols cosa d'aplicar un tractament semblant per a obtenir la informació de cada notícia for noticia in noticies: titular = noticia.find('h1').text texto = noticia.find('p').text img = noticia.find('img', 'thumbnail') if img: … -
Impostor, aucun rapport avec le courrier, la poste ou les gens de petite taille
Avec énormément de retard (non monsieur Daks, je ne vais pas renommer ma rubrique la django app du mois dernier) voici donc la django app du mois de juin. Ce mois-ci, enfin le mois dernier, je vais vous présenter Impostor une application que j’ai découvert au détour d’un tweet (de dzen je crois ) 1- Où on le trouve, comment on l’installe, tout ça quoi (et la doc) ? Deux possibilité pour le trouver, sa page github ou sa page django packages. Pas de page pypi, enfin pas encore, espérons qu’elle arrive vite. Pour l’installer, pas le choix, il faut passer par github. Un petit git clone https://github.com/samastur/Impostor.git et c’est plié. Quand à la doc, Elle se limite au readme.rst. Mais cela suffit. Et puis le readme est bien clair. Il vous expliquera comment l’installer dans votre projet django et comment vous en servir (et puis si vous continuer à lire, je vous l’expliquerais aussi) 2- Mais au fait, à quoi ça sert ? Tout simplement à se déguiser lorsque l’on se logue. D’ailleurs c’est un des meilleurs noms d’app django que j’ai pu croiser. Décrivant à la fois bien la finalité de l’app tout en étant rigolo. … -
Imatges de la web al model Django
L'altra dia estava fent una aplicació web part de la qual consisteix en aprofitar els continguts de la web anterior, continguts als que no tenim accés directe. La part de text va ser senzilla, però obtenir una imatge de la web i associar-la a un model Django va resultar una mica més interessant del que suposava. Tant que vaig pensar que potser convenia posar-ho en forma d'apunt. Per posar-ho en context vaig començar a fer una aplicació Django, la qual tenia que obtenir la imatge i guardar-la, però ja que hi era, vaig voler fer quelcom més educatiu, així que l'aplicació es va anant transformant amb codi per a descarregar-se les fotografies associades a la plana principal de meneame. Si provau el codi mirau de canviar la url que ja que amablement Ricardo em va dir que no hi havia problema en fer algunes proves, tampoc és cosa que anem putejant la web. Així doncs, aquest apunt serà un poc mescladissa d'utilitats, d' screen scrapping, de thread, processos i altres herbes. Miraré d'anar a poc a poc, però ja us aviso que hi ha de tot i molt! Definim el model El més habitual quan hom tracta amb imatges és … -
Shivling : Avoiding boilerplate in views in Django
I have been unable to find time to continue my Shiv series, however, a chat with a friend(@arihersh) who has just started learning django reminded me of a small piece of code I had written sometime back. The chat went something like this Ari Hershowitz: I’d like to have html “widgets” that have certain actions, without having to create an artificial url + view to control the widget. Maybe that’s what your framework does? Yousuf Fauzan: gimme an example Ari Hershowitz: Ok… I’ll try to describe… I want to create a search bar that goes on any page. To do this in Django, I think I need to: (1) create a search form, (2) put it into a template, (3) include the template into any other template. I also need to create a view for the search bar, with its own url, right? Yousuf Fauzan: you need a search result view Ari Hershowitz: So if I have the search bar on page x, I’ll have to call the search bar’s url from page x. Yousuf Fauzan: i.e. the url that the searcdh form will post to Ari Hershowitz: Yes, actually that’s the issue: I found that on each page I … -
Postgres user gone after lion update
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Cài đặt Django trên Dreamhost
Mình đang sử dụng dịch vụ hosting trên Dreamhost và thấy khá thú vị vì các tính năng mà nó support từ SVN, Unlimited Bandwidth và Unlimited Storage. Thú vị hơn là mình có thể cài Django trên đó để có thể thực hành được các ứng dụng nhỏ. Bài viết này sẽ cụ thể hóa cách cài đặt Django trên Dreamhost.Mặc định trên Dreamhost đã có cài Django, chúng ta có thể thấy được điều này nếu vào console python và gõ lệnh>> import django >> django.get_version()Kết quả trả về sẽ là version hiện tại của Django được cài trên host. Và mình có được version là 1.2.Hiện tại version mới nhất của Django là 1.3. Để cài đặt được version mới nhất ta làm theo các bước sau.Cài đặt Python virtualenv để có thể tự mình cài đặt các Python package. Kiểm tra trang virtualenv pypi để lấy bản mới nhất.wget http://pypi.python.org/packages/source/v/virtualenv/virtualenv-1.6.3.tar.gz tar xzf virtualenv-1.6.3.tar.gz python virtualenv-1.6.3/virtualenv.py $HOME/local rm -rf virtualenv* export PATH=$HOME/local/bin:$PATHBạn nên sửa lại ~/.bashrc như sauexport PATH=$HOME/local/bin:$PATHKiểm tra lại đường dẫn đến python bằng lệnh which python, kết quả trả về là /home/youruser/local/bin/python chứ không phải là /usr/bin/python.Giờ chúng ta có thể cài (cập nhật) … -
Opportunism and other approaches to action in Software Architecture
Venkatesh Rao's onthology of decision making can be a source of inspiration for software architectures. I discuss four approaches to action taking in web development. -
A taste of the Django on inside Mozilla, Sheriffs Duty
One of the many great things about working for Mozilla is that everything we do is Open Source. Even our wiki is open (however we have an internal wiki for corporation boring stuff such as meeting rooms, HR etc.) Last week I wrote an internal application for Mozilla's build engineers. Essentially it's a roster that lists one user per day and it's helped by being visualized as a calendar and as a vCal export. It's very unlikely that anybody outside Mozilla will find this particularly useful. But who knows, perhaps other companies have needs to take turns to sheriff build machines. Anyway, the project was easy to write because we have something called Playdoh. It's a set of nifty and useful settings and a folder structure and it comes with a submodule called "playdoh-lib" which is stuffed with lots of useful packages that you'll most likely want to use. If you browse Playdoh on Github it might look like a lot of stuff but after a second look you'll see that there's actually almost no code. So don't you dare to play the "bloat card"! :) What this app uses is TastyPie for the REST API which was awesome by … -
A taste of the Django on inside Mozilla, Sheriffs Duty
One of the many great things about working for Mozilla is that everything we do is Open Source. Even our wiki is open (however we have an internal wiki for corporation boring stuff such as meeting rooms, HR etc.) Last week I wrote an internal application for Mozilla's build engineers. Essentially it's a roster that lists one user per day and it's helped by being visualized as a calendar and as a vCal export. It's very unlikely that anybody outside Mozilla will find this particularly useful. But who knows, perhaps other companies have needs to take turns to sheriff build machines. Anyway, the project was easy to write because we have something called Playdoh. It's a set of nifty and useful settings and a folder structure and it comes with a submodule called "playdoh-lib" which is stuffed with lots of useful packages that you'll most likely want to use. If you browse Playdoh on Github it might look like a lot of stuff but after a second look you'll see that there's actually almost no code. So don't you dare to play the "bloat card"! :) What this app uses is TastyPie for the REST API which was awesome by … -
Translated text images for lazy programmers
In a previous post about django translations in this blog, I shared how to achieve a quick system that allowed me to manage translations stored in models and served using a template tag. In this post I will explain how to serve images that contain translated text and, hence, a localized image exists for each language. In my case, images are referenced from <img> HTML tags in templates and from CSS files. First of all we must create a basic structure in our img/ and css/ media folders, creating inside a directory for each language code we will use. For example, if we have two languages -- english and spanish -- we would create img/en/, img/es/, css/en/ and css/es/. In the CSS folders, the same files must be initially copied. If we have, for instance, just one style.css file, it must be both in css/en/style.css and css/es/style.css: css/ en/ style.css es/ style.css For the images, we should create the images that will be translated into each language code folder. All CSS files will reference the non-translated images in the same way, but their own file path to the translated image. I'll give an example. Let's say we have one background … -
A common Django/Postgres unicode fail
If you just installed postgres and created a database, Django will probably fail to bring you unicode happiness. The chances are that your site suffers from this error, even if you have not seen it yet. How to spot and fix "DatabaseError: value too long for type character varying"? Read the blog post! -
Where Django programming and Google Analytics meet
We just recently discovered an issue where a programming decision affected the ease (or lack thereof) of establishing goal funnels in Google Analytics. What we also discovered was that it was completely avoidable with a little better communicatioin between our Django programming staff and our analytics staff. As is typical ... -
Sử dụng Amazon SES với Django
Amazon Simple Email Service (Amazon SES) là một giải pháp email dễ dùng và hiệu quả cho các ứng dụng. Tuy Amazon SES đang được phát triển ở giai đoạn beta nhưng nó đã đáp ứng tương đối đầy đủ nhu cầu nhận và gửi mail.Để đăng ký sử dụng Amazon SES chúng ta làm theo các bước hướng dẫn này để xác minh địa chỉ email cần sử dụng. Nếu làm việc trên môi trường Windows chúng ta cần đọc thêm hướng dẫn này nữa. Trên môi trường Ubuntu khi thực hiện quá trình verify email có thể sẽ gặp thông báo lỗi như là "Can't locate XML/LibXML.pm in @INC....". Lỗi này xảy ra khi máy của bạn chưa có thư việc XML của Perl. Để khắc phục bạn cài thêm 2 thư viện của Perl bằng dòng lệnhsudo apt-get install libio-socket-ssl-perlsudo apt-get install libxml-libxml-perlSau khi verify email thành công chúng ta có thể thực hiện gửi mail, nhưng chỉ gửi và nhận với địa chỉ email mà đã được đăng ký, chủ yếu dùng để debug trước khi thực hiện tiếp quá trình đăng ký Production để gửi email đến các địa chỉ khác.Công việc tiếp theo là … -
Filtering querysets in django.contrib.admin forms
I make extensive use of the django admin interface. It is the primary tool for our support team to look at user data for our product, and I have stretched it in many ways to suit my needs. One problem I often come back to is a need to filter querysets in forms and formsets. Specifically, the objects that should be presented to the admin user in a relationship to the currently viewed object should be filtered. In most cases, this is something as simple as making sure the Person and the Units they work at are within the same company. There is a simple bit of boilerplate that can do this. You need to create a custom form, and attach this to the ModelAdmin for the parent object: {% highlight python linenos %} from django.contrib import admin from django import forms from models import Person, Unit class PersonAdminForm(forms.ModelForm): class Meta: model = Person def __init__(self, *args, **kwargs): super(PersonAdminForm, self).__init__(*args, **kwargs) # This is the bit that matters: self.fields['units'].queryset = self.instance.company.units class PersonAdmin(admin.ModelAdmin): form = PersonAdminForm {% endhighlight %} In actuality, it is a little more complicated than this: you need to test if the selected object has a company, … -
Django: Using Caching to Track Online Users
Recently I wanted a simple solution to track whether a user is online on a given Django site. The definition of "online" on a site is kind of ambiguous, so I'll define that a user is considered to be online if they have made any request to the site in the last five minutes. I found that one approach is to use Django's caching framework to track when a user last accessed the site. For example, upon each request, I can have a middleware set the current time as a cache value associated with a given user. This allows us to store some basic information about logged-in user's online state without having to hit the database on each request and easily retrieve it by accessing the cache.My approach below. Comments welcome.In settings.py:# add the middleware that you are about to create to settingsMIDDLEWARE_CLASSES = ( .... 'middleware.activeuser_middleware.ActiveUserMiddleware', ....)# Setup caching per Django docs. In actuality, you'd probably use memcached instead of local memory.CACHES = { 'default': { 'BACKEND': 'django.core.cache.backends.locmem.LocMemCache', 'LOCATION': 'default-cache' }}# Number of seconds of inactivity before a user is marked offlineUSER_ONLINE_TIMEOUT = 300# Number of seconds that we will keep track of inactive users for before # their last … -
Python and OS X Lion
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Convention Over Configuration: Django Settings
I've been working with Django for over five years. Even though **I don't consider myself as a programmer**, one of the advantages I seem to have over less experienced Django developers is that I've developed (together with <a href="http://www.syneus.fi/" title="Syneus Solutions -- In Finnish">our team</a>) strong conventions on how I work. This makes developing faster and generally more enjoyable. Conventions are a tool for efficient workflow and to help read and understand code by other people better. Like so many tools, conventions too can be taken to extremes to the point when then they become magic (Rails, anyone), which in Python community is <a href="http://www.reddit.com/r/Python/comments/ex54j/seeking_clarification_on_pylonsturbogearspyramid/c1bo1v5">considered a bad practice</a>. The Python community has a name for code that feels right: that kind of code is _pythonic_. Good, pythonic conventions are logical and easy to remember but also explicit. In other words good conventions should make sense when you see them first time. Django has many documented conventions (like that models should live in `models.py` and views in `views.py`) and even <a href="https://docs.djangoproject.com/en/1.3/internals/contributing/#coding-style">coding guidelines</a> but there are many places that could use more stronger or better ones. This article is first in a series of discussing conventions related to Django. My goal … -
Convention Over Configuration: Django Settings
This is a first article in a series about DRY and pythonic conventions for Web development with Django. The goal is to share and discuss common problems in everyday Django development where there is no documentation nor an obvious way of do it. -
How to always exclude specific Django applications from unit testing
Sometimes your Django project will include applications whose unit tests will never pass. In this post, I will explain a quick fix for this, and, probably more usefully, try to explain how and why I developed the code. -
How to always exclude specific Django applications from unit testing
Sometimes your Django project will include applications whose unit tests will never pass. In this post, I will explain a quick fix for this, and, probably more usefully, try to explain how and why I developed the code.