Django community: Community blog posts RSS
This page, updated regularly, aggregates Community blog posts from the Django community.
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Generating NCX files with Python
With the help of fellow Python developer Matt Harrison's excellent Ebook Formatting: KF8, Mobi & EPUB, we managed to create pretty decent looking Kindle and ePub versions of Two Scoops of Django. One of many things we did was focus on providing an excellent table of contents. Of course we provided one inside the content of the book, but much like the PDF version we also provided one that various ebook readers can display in sidebars or drop down menus. Unfortunately, building this navigation isn't well documented (except for Matt's book), and I've yet to see any good ways to generate it via code. Which is why I present the following code. It looks at the HTML that KindleGen and ePub generators demand and pulls from it a chapter-based table of contents. Then constructs a .ncx file, which is what ebook readers use to generate the sidebar/dropdown table of contents. Our requirements: Jinja2 Django BeautifulSoup4 And now the code: #!/usr/bin/python # -*- coding: utf-8 -*- from bs4 import BeautifulSoup from django.utils.text import slugify from jinja2 import Template TEMPLATE = Template("""<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE ncx PUBLIC "-//NISO//DTD ncx 2005-1//EN" "http://www.daisy.org/z3986/2005/ncx-2005-1.dtd"> <ncx xmlns="http://www.daisy.org/z3986/2005/ncx/" version="2005-1" xml:lang="en"> <head> <!-- The content of dtb:uid must ... -
Bundling dependencies
This post is about maintenance programming and the issue of Open Source dependencies that may need customising. It compiles some of my current thoughts, but I'm also eager to find out what other people do. 3 approaches to dependencies Pure dependency The source code of the dependency does not become a part of your project in any way. For a web project with Python and virtualenv/pip, you would just list the project name and version in requirements.txt, and it will be installed when you deploy your project. This is by far the easiest approach to dependencies. Forked dependency You create a fork of the library (usually hosted publicly, but not necessarily) and add to it the changes you need. You then use this fork from your main project. This is done either in the hope that bug fixes and feature additions that you make will be merged into the original, so that you won't have to maintain your fork forever, or with the aim of keeping your changes small enough that it will always be easy to merge in fixes from upstream. Bundled dependency You take a copy of the library, and include it directly into your own source code, ... -
Django 1.5 on Webfaction
The setup of a Django application on Webfaction is really easy using their one-click-installer. But this setup is really static and surely not the best option to use for Django. Luke Plant wrote about setting up Django with gunicorn on Webfaction in his blog, I will write about setting up Django 1.5 with Apache and mod_wsgi without the Django one-click-installer but the mod_wsgi one (mod_wsgi 3.4 / Python 2.7). The setup won't be the fastest Django setup in the world, but it will work. It's basically an update for my old blog post covering Django 1.3: Set up a mod_wsgi application and create a website in the Webfaction control panel. Log into shell and goto your newly created app. Create a virtualenv and a folder for your project files (maybe you want to check out from a VCS), activate the virtualenv and install Django an whatever you need. Edit the default wsgi.py create by the django-admin.py startproject command: """ WSGI config for tools_project project. This module contains the WSGI application used by Django's development server and any production WSGI deployments. It should expose a module-level variable named ``application``. Django's ``runserver`` and ``runfcgi`` commands discover this application via the ``WSGI_APPLICATION`` setting. ... -
Django 1.5 on Webfaction
The setup of a Django application on Webfaction is really easy using their one-click-installer. But this setup is really static and surely not the best option to use for Django. Luke Plant wrote about setting up Django with gunicorn on Webfaction in his blog, I will write about setting up Django 1.5 with Apache and mod_wsgi without the Django one-click-installer but the mod_wsgi one (mod_wsgi 3.4 / Python 2.7). The setup won't be the fastest Django setup in the world, but it will work. It's basically an update for my old blog post covering Django 1.3: Set up a mod_wsgi application and create a website in the Webfaction control panel. Log into shell and goto your newly created app. Create a virtualenv and a folder for your project files (maybe you want to check out from a VCS), activate the virtualenv and install Django an whatever you need. Edit the default wsgi.py create by the django-admin.py startproject command: """ WSGI config for tools_project project. This module contains the WSGI application used by Django's development server and any production WSGI deployments. It should expose a module-level variable named ``application``. Django's ``runserver`` and ``runfcgi`` commands discover this application via the ``WSGI_APPLICATION`` setting. ... -
Django 1.5 on Webfaction
The setup of a Django application on Webfaction is really easy using their one-click-installer. But this setup is really static and surely not the best option to use for Django. Luke Plant wrote about setting up Django with gunicorn on Webfaction in his blog, I will write about setting up Django 1.5 with Apache and mod_wsgi without the Django one-click-installer but the mod_wsgi one (mod_wsgi 3.4 / Python 2.7). The setup won't be the fastest Django setup in the world, but it will work. It's basically an update for my old blog post covering Django 1.3: Set up a mod_wsgi application and create a website in the Webfaction control panel. Log into shell and goto your newly created app. Create a virtualenv and a folder for your project files (maybe you want to check out from a VCS), activate the virtualenv and install Django an whatever you need. Edit the default wsgi.py create by the django-admin.py startproject command: """ WSGI config for tools_project project. This module contains the WSGI application used by Django's development server and any production WSGI deployments. It should expose a module-level variable named ``application``. Django's ``runserver`` and ``runfcgi`` commands discover this application via the ``WSGI_APPLICATION`` setting. ... -
A whole load of Kickstarting
When I launched my Kickstarter campaign, I didn't quite expect this level of response... It's an odd thing, the internet. Back when I was just starting out doing freelance work - at the ripe old age of fifteen - I remember my mother being slightly bemused that people on the internet were giving me money. Of course, that was for work I had already completed, but in this modern age, it's now possible to raise money before you've even started. My Kickstarter campaign was a simple request - I have some free time, a specific project to build, and a pretty good idea of how to build it. Why not see if the community would contribute? NoteI almost added a £20,000 stretch goal to remove MySQL support entirely. Almost. Oh, how they did. The Kickstarter closed at a whopping £17,952 - 718% of my original £2,500 request. Not only that, but it was funded in 65 minutes and my highest stretch goal (£7,000) was reached in four hours. That Friday was one of the most surreal days of my life - watching the Kickstarter page and Twitter as both donations and messages of support came streaming in. 507 people contributed ... -
A helper script for runserver
My Django runserver shortcut script This is a little shell script I save as rs, put on my path, and use as a shortcut to start the Django development server. It has several features that make me more productive: It’s shorter to type than python manage.py runserver. It recognizes what project I’m in and runs many of them on different ports. It opens the web site’s front page in my browser. Running my most important projects on separate ports has a couple of advantages: I can run several simultaneously. My browser can differentiate the projects. When everything runs at localhost:8000, my browser might cache a file like style.css and have no way of knowing when I switch projects and style.css is completely different. If one project is at localhost:8001 and the other is at localhost:8002, the cache keeps them separate. It opens the current site in my browser (after giving the server a few seconds to start) because that’s typically what I do next anyway, and it saves me having to keep track of which project uses which port. If I already have the site open in my browser, I just pass “.” as the first command line argument and ... -
Announcing WSGI X-Sendfile: High-Performance File Transfer for Python/WSGI Applications
I'm pleased to announce the first public release of WSGI X-Sendfile, a library that lets your Python/WSGI application serve static files via your Web server. Modern Web servers like Nginx are generally able to serve files faster, more efficiently and more reliably than any Web application they host. These servers are also able to send to the client a file on disk as specified by the Web applications they host. This feature is commonly known as X-Sendfile. This simple library makes it easy for any WSGI application to use X-Sendfile, so that they can control whether a file can be served or what else to do when a file is served, without writing server-specific extensions. Use cases include: Restrict document downloads to authenticated users. Log who’s downloaded a file. Force a file to be downloaded instead of rendered by the browser, or serve it with a name different from the one on disk, by setting the Content-Disposition header.This code has been used in production for three years in our Django application, but is now being released as beta in case there are bugs that haven't become evident in our systems. Get it while it's hot! -
Announcing WSGI X-Sendfile: High-Performance File Transfer for Python/WSGI Applications
I'm pleased to announce the first public release of WSGI X-Sendfile, a library that lets your Python/WSGI application serve static files via your Web server.Modern Web servers like Nginx are generally able to serve files faster, more efficiently and more reliably than any Web application they host. These servers are also able to send to the client a file on disk as specified by the Web applications they host. This feature is commonly known as X-Sendfile.This simple library makes it easy for any WSGI application to use X-Sendfile, so that they can control whether a file can be served or what else to do when a file is served, without writing server-specific extensions. Use cases include:Restrict document downloads to authenticated users.Log who’s downloaded a file.Force a file to be downloaded instead of rendered by the browser, or serve it with a name different from the one on disk, by setting the Content-Disposition header.This code has been used in production for three years, but is now being released as beta in case there are bugs that haven't become evident in our systems.Get it while it's hot! -
Progress Report for March 26th
Reflections on my progress and plans*Update: I had thought I had previously published this post on March 26th, but obviously I did not.The last week has been hectic, but quite productive for Team Django. The team has created a new version of our project poster. Additionally, we have been working on ticket #19224, and creating a rough version of our final presentation slides. A piece of interesting news is the Schema Migrations for Django kickstarter. Andrew Godwin, creator and maintainer of Django South, has proposed adding schema migrations to the Django core. Yes, this isn't an "official" Django proposal. Yes, he did get the approval of the other core contributors. He has raised an incredible amount of money, $23,000 as of March 26th. -
Satchmo 0.9.2 Released
Satchmo 0.9.2 is released. This release of satchmo includes many updates and improvements. -
Editar y traducir inline en Django fácilmente
Desde Yaco nos traen las aplicaciones pluggables django-inlinetrans y django-inplaceedit que permiten editar traducciones de templates y objetos de nuestros modelos desde el frontend de nuestro proyecto... -
Dropbox file upload handler for django
Dropbox announced new pro plans last week and some accounts have had their storage size doubled. Wouldn't it be wonderful if we could upload all our files to dropbox from our django webapp? In this post, I write a custom file upload handler that will upload files from our application to dropbox. Let us see how to use the custom file upload handler. Install the Dropbox Python SDK before you setup your django app to handle the file uploads. In your settings.py, add the following attributes (with the values filled): DROPBOX_APP_KEY = "" DROPBOX_APP_SECRET_KEY = "" DROPBOX_APP_ACCESS_TOKEN = "" DROPBOX_APP_ACCESS_TOKEN_SECRET = "" # Optional values below # The folder where you want the files uploaded. # Example: /Public or / DROPBOX_FILE_UPLOAD_FOLDER = "" # The value below may be either 'app_folder' or 'dropbox' DROPBOX_ACCESS_TYPE = "" The DROPBOX_APP_KEY and DROPBOX_APP_SECRET_KEY are provided to you when you create a new dropbox app. Fetching the access token and access token secret is outside the scope of this blog post but you can follow the Getting Started Guide until the Get an access token section and then paste the access token key and secret in the DROPBOX_APP_ACCESS_TOKEN and DROPBOX_APP_ACCESS_TOKEN_SECRET attributes respectively. Add the ... -
Introduction to Django Selenium Testing
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Go Open Data
What started as a brief conversation between myself and Michael Druker almost a year ago has come to life. On Saturday, May 11th people from Windsor to Ottawa are going to come together at the University of Waterloo School of Pharmacy for GO Open Data, a one day conference. The conference aims to bring together people from across Ontario and across the various interests related to open data to enjoy 8 talks, 2 panels, and an exhibition called Open Data Alley. Citizens, journalists, developers, administrators, CIOs, librarians, different people from all the areas connected to this fusion of technology and policy will be in attendance. That alone will make for an exciting day. It is thanks to the many partners from the Region of Waterloo, the City of Waterloo and the University of Waterloo that such a small idea has become so successful. We have amazing speakers like Ontario Information and Privacy Commissioner Dr. Ann Cavoukian, and up and coming speakers like James McKinney from Open North in Montreal. You can hear an interview with Dr. Cavoukian on the lawful access episode of Jessie Brown's Search Engine podcast. The rest of the schedule can be found online: http://go-opendata.ca/ The conference ... -
2.3.6 release
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A Survey on Software Quality
A Survey on Software Quality Want to help me graduate, and make the software industry a better place for us all? Great! I am writing my graduate report on the topic of software quality, metrics, and visualization. The report will ... -
A Survey on Software Quality
A Survey on Software Quality Want to help me graduate, and make the software industry a better place for us all? Great! I am writing my graduate report on the topic of software quality, metrics, and visualization. The report will ... -
PyCon 2013 Recap---Teaching and Learning with the Python Community
Caktus had a wonderful time at this year’s PyCon conference. We believe strongly in supporting our developers in their quest to become the best coders that they can be and think that being at PyCon is a great way for them to learn about what’s going on in the Python community. We sent ten people to the conference to work at our booth and attend conference events. The organizers of PyCon, headed by Jesse Noller, put on an amazing event that created a space for people to meet face to face in order to work and learn together. During the opening keynote presentation, Jesse Noller shared with PyCon his parting gift to the PyCon community before relinquishing the reins after his last year of heading PyCon. He told the audience that the Python Software Foundation was providing a Raspberry Pi computer to each of the 2,500 conference attendees in the hopes that they would build awesome projects and share them widely. This parting gift to the community was part of his contribution to enable pythonistas as he said to, "build a legacy for Python and the community that enriches and enlivens the next generation of programmers" by "infecting everyone with ... -
Multi-file find and replace for {% url “quoted” %} tag in Django 1.5
Django 1.5 deprecates the old {% url %} tag style and uses the new one. The new one needs the url name to be quoted. So instead of {% url public_index %} it must be {% url "public_index" %}. You’ll get an error: ‘url’ requires a non-empty first argument. The syntax changed in Django 1.5, see the docs. Instead of adding quotes to each one in each template manually, I wanted a multi-file find and replace regex. Examples abound of using find with xargs and sed. But here’s a simple Python script and example usage to do just that. Note that it updates the files in-place. Make sure you have a backup and/or they’re committed to version control just in case something goes wrong and messes up your templates. You’ve been warned. Here’s a simple find and replace Python script: import sys import os import re def main(argv=None): if argv is None: argv = sys.argv if len(argv) < 4: print """ Usage: %s find replace filename.txt [filename2.txt...] """ % argv[0] exit find = argv[1] replace = argv[2] filepaths = argv[3:] for filepath in filepaths: text = open(filepath).read() #print re.sub(find, replace, text) new_text = re.sub(find, replace, text) if new_text != text: ... -
Best practices with Django on WebFaction
This blog post is about deploying Django apps. It is addressed primarily to WebFaction, but applies to any other hosts else with one-click installers for this kind of app. First, many thanks to WebFaction for their great service and support. I've got very few complaints about them in general. However, I think their approach to setting up Django projects is far from ideal, and makes life harder than it needs to be. The WebFaction Django docs tell us to create a new Django app by using the control panel and choosing an app of type ‘Django’ and then choosing your Django version. This will install an Apache instance with mod_wsgi, and a copy of the Django sources, and set up a basic Django app skeleton. There are lots of problems with this: What happens when there is a security issue with Django? The user will need to have an upgrade mechanism. This is covered in the docs, but it is an 11 step process. And this process is a process they will first have to do in their development environment for testing, in some way, and then again on their live box. How many people will actually do that, especially ... -
Github test commit reports for teams
I recently wrote githubinfo. It is a quick and handy script that queries the github API of one or more organizations and gives you a simple report on the amount of commits with tests in the last week. I figured it could be useful to others, so I made it available on pypi, including reasonable documentation of course: https://pypi.python.org/pypi/githubinfo . You can pip install githubinfo (or put it in your buildout). It is just a simple single command and the output looks like this: $ testcommitinfo loading project neerslagradar-site loading project ... ... We want more and better testing. For a quick and dirty quantity indication ('more'), here are the commits that have the string 'test' in of of the commit's touched filenames. Period: 8 days. Github organizations that I queried: ddsc, lizardsystem, nens Projects sorted by amount of commits with tests ----------------------------------------------- lizard-neerslagradar: 11 (25%) lizard-progress: 3 (9%) radar: 1 (33%) ... Committers sorted by amount of commits with tests ------------------------------------------------- Reinout van Rees: 12 (11%) Remco Gerlich: 3 (6%) Arjan Verkerk: 2 (8%) ... Goal I wrote it because we wanted to improve our development process at Nelen & Schuurmans. We wanted more tests. So I wrote a ... -
Core Concepts of Django Forms
In my opinion, the concepts behind Django's non-model forms can be listed in just three (3) bullets: Forms render HTML. Forms are "just" Python constructs. Forms validate dictionaries (Python's Key/Value structure). Let's dig in! Forms render HTML. If I construct a Django form: # myapp/forms.py from django import forms class MyForm(forms.Form): title = forms.CharField(required=True) I can render it in a template, or for better clarity in this post, the Python REPL: >>> from myapp.forms import MyForm >>> f = MyForm() >>> f <__main__.MyForm object at 0x1016c6990> >>> print(f) <tr><th><label for="id_title">Title:</label></th> <td><input id="id_title" name="title" type="text" /></td></tr> You can even see this done with initial values in the Django docs: https://docs.djangoproject.com/en/1.5/ref/forms/api/#django.forms.Form.initial Forms are "just" Python constructs. I believe it was Alex Gaynor who said back in 2008 that Django forms were "just" Python constructs. He's right: >>> from myapp.forms import MyForm >>> # class >>> MyForm <class 'myapp.forms.MyForm'> >>> # object >>> form = MyForm() >>> form <myapp.forms.MyForm object at 0x1023f1450> >>> # iterable >>> [x for x in form] [<django.forms.forms.BoundField object at 0x102495990>] >>> [x for x in form.fields] ['title'] >>> # dictionary-like >>> form.fields['title'] <django.forms.fields.CharField object at 0x1024a17d0> Understanding the structure of Django forms is really useful. This structure is ... -
Core Concepts of Django Forms
In my opinion, the concepts behind Django's non-model forms can be listed in just three (3) bullets: Forms render HTML. Forms are "just" Python constructs. Forms validate dictionaries (Python's Key/Value structure). Let's dig in! Forms render HTML. If I construct a Django form: # myapp/forms.py from django import forms class MyForm(forms.Form): title = forms.CharField(required=True) I can render it in a template, or for better clarity in this post, the Python REPL: >>> from myapp.forms import MyForm >>> f = MyForm() >>> f <__main__.MyForm object at 0x1016c6990> >>> print(f) <tr><th><label for="id_title">Title:</label></th> <td><input id="id_title" name="title" type="text" /></td></tr> You can even see this done with initial values in the Django docs: https://docs.djangoproject.com/en/1.5/ref/forms/api/#django.forms.Form.initial Forms are "just" Python constructs. I believe it was Alex Gaynor who said back in 2008 that Django forms were "just" Python constructs. He's right: >>> from myapp.forms import MyForm >>> # class >>> MyForm <class 'myapp.forms.MyForm'> >>> # object >>> form = MyForm() >>> form <myapp.forms.MyForm object at 0x1023f1450> >>> # iterable >>> [x for x in form] [<django.forms.forms.BoundField object at 0x102495990>] >>> [x for x in form.fields] ['title'] >>> # dictionary-like >>> form.fields['title'] <django.forms.fields.CharField object at 0x1024a17d0> Understanding the structure of Django forms is really useful. This structure is ... -
Now it's your turn
I just watched Jacob's talk on "Porting Django apps to Python 3", and realised it was time to tackle my own small Django apps. The problem with porting is that you need your dependencies to be ported first. But now that Django has Python 3 support, the finger is no longer pointing at Django — it is pointing at all of us with Django apps that have only Django as a dependency (or other dependencies that are already ported to Python 3). As Jacob put it at the end of the talk, it’s your turn. So, I took the challenge, and here is a walk through of what you need to do, and what I had to do: Find an app/library you've written that has very few dependencies, or all dependencies already ported to Python 3. In my case, django-easyfilters. Not a massively popular library, but it has had over 1000 downloads, and I know some people use it. Install tox and create a tox.ini file to run your test suite on more than one version. Start with all the Django versions you want to support, with Python 2.x combinations (Python 2.6 and 2.7 recommended), and Python 3.3. My tox.ini ...
