Django community: RSS
This page, updated regularly, aggregates Community blog posts from the Django community.
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Introducing Moya Techblog, a Blogging Engine for Coders and Photographers
I've had a blog on my vanity domain for nearly a decade now. For the last 6 years, it has been powered by Django Techblog, which I wrote out of my frustration with syntax highlighting plugins in Wordpress. Techblog has happily served my blog those 6 years, with only minor hiccups when I half-heartedly ported the code to the latest Django. There was nothing terribly wrong with Django Techblog; it had multiple blogs, tags, search etc., but there were some annoyances that I didn't have the motivation to do much about. The custom markup system I used was clever, but I would often forget the syntax! The support for images was rudimentary and the single-threaded comment system wouldn't notify me of replies. So fast forward 6 years and the time is right to build a new blog system to fix the old niggles. This time around I had same requirements for syntax highlighting in both posts and comments, with a new requirement to be able to manage and display photographs, while supporting the same multi-blog and feed URLs. Moya Tech Blog The new blog engine running my blog is Moya Tech Blog. Posts and comments use markdown (by default), which … -
Nginx proxying to nginx: getting gzip compression to work
At work we use gunicorn as our wsgi runner. Like many, gunicorn advises you to run the nginx webserver in front of it. So on every server we have one or more websites with gunicorn. And an nginx in front. Nginx takes care, of course, of serving the static files like css and javascript. Some gzipping of the results is a very, very good idea: server { listen 80; server_name my.great.site; ... gzip on; gzip_proxied any; gzip_types text/css text/javascript text/xml text/plain application/javascript application/x-javascript application/json; .... } Two notes: The default is to only gzip html output. We also want javascript and json. So you need to configure gzip_types. (I copy-pasted this from one of my config files, apparently I needed three different javascript mimetypes... Perhaps some further research could strip that number down.) gzip_proxied any tells nginx that gzipping is fine even for proxied requests. Proxied requests? Yes, because we have a lot of servers and all external traffic first hits our main nginx proxy. So: we have one central server with nginx that proxies requests to the actual servers. So: nginx behind nginx: server { listen 443; server_name my.great.site; location / { proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header Host $http_host; proxy_redirect … -
Looking for an experienced Python Developer
My client, WildFoundry, is looking for an experienced Python developer to join us. We work in the field of IoT, and you will get to work with a variety of really cool technologies. Here's the job description: Job Description WildFoundry is seeking a senior Python web application developer on a 8 month contract to help us in the development of the dataplicity Internet-of-Things platform (dataplicity.com). You would be expected to work from your home or own office most of the time and very high quality candidates based in Slovakia, Poland and the United Kingdom will be considered. This is an unbeatable opportunity to work from home, earn excellent rates and join in with fast growing projects. Our web application runs on a combination of Python and django, and we’re really pushing the boundaries of what we can do with both of them. You will be challenged. You’ll be playing with everything from Amazon and Linode services to embedded PCs, and a bunch of new web technologies. You’ll be writing daemons, UI for django apps, code for embedded systems, websockets. We are seeking a top calibre developer well regarded in the community. If you’ve contributed code to OSS apps or have … -
Buildout 2.5.0 has much nicer version conflict reporting
We use buildout for all our django projects. Nothing wrong with pip, but buildout has extension possibilities build-in (for creating directories, installing user crontabs, local development checkouts and many more) that are quite helpful. And it works better when you need to use system packages (gdal, mapnik, etc). One area where buildout could use some improvement was the version conflict reporting. Let's say you have pinned django to 1.6.6 (old project that I'll upgrade to 1.8 this week) and you add the django debug toolbar. This is the error you get: The constraint, 1.6.6, is not consistent with the requirement, 'Django>=1.7'. While: Updating django. Error: Bad constraint 1.6.6 Django>=1.7 First things first. An easy one is to improve the wording of the message: While: Installing django. Error: The requirement ('Django>=1.7') is not allowed by your [versions] constraint (1.6.6) Now... so there is some package that requires at least django 1.7. But which one? Buildout did not tell you. Which would mean you'd have to grep in all your requirements' sub-requirements for which package actually requires the offending "django>=1.7"... I've now added some internal logging that stores which package required which dependency. After an error occurs, the list is searched for … -
Ember application structure
Ember.js applications are divided into multiple files and folders. All of which makes sense when we get to know what is where, so lets take a look on Ember application structure. -
Setting up ember-cli development environment with ember 2.1
In a series of tutorials starting with this one I'll try to showcase ember.js framework for building fronted web applications. As a backend there will be Django Rest Frameowork and more. As times change and JavaScript frameworks don't just download to your static folder I'll start with setting up Ember.js development environment with ember-cli. -
We need less powerful languages
Many systems boast of being ‘powerful’, and it sounds difficult to argue that this is a bad thing. Almost everyone who uses the word assumes that it is always a good thing. The thesis of this post is that in many cases we need less powerful languages and systems. Before I get going, I should say first of all that very little in this post is original. The train of thought behind it was set off by reading Hofstadter's book Gödel, Escher, Bach — an Eternal Golden Braid which helped me pull together various things in my own thinking where I've seen the principle in action. Philip Wadler's post on the rule of least power was also formative, and most of all I've also taken a lot from the content of this video from a Scala conference about everything that is wrong with Scala, which makes the following fairly central point: Every increase in expressiveness brings an increased burden on all who care to understand the message. My aim is simply to illustrate this point using examples that might be more accessible to the Python community than the internals of a Scala compiler. I also need a word about definitions. … -
MIT uses Evennia!
Evennia was recently used as a test bed to train an AI system to attempt to play a MUD as a human would - by only reading and understanding the text on the screen. Researchers at MIT (Massachusetts Institute of Technology) recently presented the paper Language understanding for Text-based games using Deep reinforcement learning (PDF) at a conference on natural language processing. A summary is in the MIT press release.I was contacted by these fine folks some time ago so I knew they had plans to use Evennia for their research. It's great to see they now have an article out on it! Evennia devs are also mentioned in the acknowledgements - so something for the Evennia dev community to be proud of! MUDs are tricky The main complication for an AI playing a MUD is that the computer has no access to the actual game state but must try to surmise how well it's doing only from the text given (same as a human would). The researchers compare the results from a range of deep-learning neural network algorithm that they train to play. To test their AI, the researchers first used Evennia to build a simple training "Home World": … -
How to send Jabber (XMPP) messages from Django
Did you ever want to have a simple Django notification bot? An intranet one which just sends you (or someone you tell it to) Jabber messages when certain events occur? So did I. Please, welcome: django-jabber. -
How to send Jabber (XMPP) messages from Django
Did you ever want to have a simple Django notification bot? An intranet one which just sends you (or someone you tell it to) Jabber messages when certain events occur? So did I. Please, welcome: django-jabber. -
Tip: How to get a single object`s value with Django ORM
There are times when you want to get a single field of a single object in the database. For example, just get the headline of the blog post #1, not fetching it’s body. How do you do it in a usual way? >>> BlogPost.objects.only('headline').get(pk=1).headline 'Hello world' # Or maybe even this way: >>> BlogPost.objects.values('headline').filter(pk=1)[0]['headline'] 'Hello world' Recently I’ve stumbled upon a shorter one: -
Tip: How to get a single object`s value with Django ORM
There are times when you want to get a single field of a single object in the database. For example, just get the headline of the blog post #1, not fetching it’s body. How do you do it in a usual way? >>> BlogPost.objects.only('headline').get(pk=1).headline 'Hello world' # Or maybe even this way: >>> BlogPost.objects.values('headline').filter(pk=1)[0]['headline'] 'Hello world' Recently I’ve stumbled upon a shorter one: -
When you shouldn’t use the Django admin
In case you’ve thought I detest django.contrib.admin — by no means. Actually it’s one of the Django’s greatest features, I really love it. In most cases. Here’s a real life story. We’ve had to quickly put up the first version of an intranet claim tracking system, and one of our developers was just crazy about the Django admin… So why not, we’ve got along with the stock interface as the primary one for ... -
When you shouldn’t use the Django admin
In case you’ve thought I detest django.contrib.admin — by no means. Actually it’s one of the Django’s greatest features, I really love it. In most cases. Here’s a real life story. We’ve had to quickly put up the first version of an intranet claim tracking system, and one of our developers was just crazy about the Django admin… So why not, we’ve got along with the stock interface as the primary one for ... -
A Quick Introduction to Backbone
Who Uses Backbone? airbnb, newsblur, disqus, hulu, basecamp, stripe, irccloud, trello, … Why? http://backbonejs.org/#FAQ-why-backbone It is not a framework Backbone is an MVP (Model View Presenter) javascript library that, unlike Django, is extremely light in its use of conventions. Frameworks are commonly seen as fully-working applications that run your code, as opposed to libraries, where you import their code and run it yourself. Backbone falls solidly into the latter category and it’s only through the use of the Router class that it starts to take some control back. Also included are View, Model and Collection (of Models), and Events, all of which can be used as completely standalone components and often are used this way alongside other frameworks. This means that if you use backbone, you will have much more flexibility for creating something unusual and being master of your project’s destiny, but on the other hand you’ll be faced with writing a lot of the glue code yourself, as well as forming many of the conventions. Dependencies Backbone is built upon jQuery and underscore. While these two libraries have some overlap, they mostly perform separate functions; jQuery is a DOM manipulation tool that handles the abstractions of various browser … -
Initial Data in Django
I’ve struggled to find an ideal way to load initial data for Django projects. By “initial data,” I’m referring to the kind of data that you need on a new system for it to be functional, but could change later. These are largely lists of possible choices, such as time zones, countries, or crayon colors. -
Speeding up a Django web site without touching the code
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 … -
Comics v2.2.0 released with Django 1.5 support
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. -
Comics v2.3.0 released with better mobile support
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 … -
Comics v2.2.0 released with Django 1.5 support
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. -
Comics v2.3.0 released with better mobile support
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 … -
Django under the hood: documentation workshop - Mikey Ariel
(One of my summaries of a talk at the 2015 django under the hood conference). Documentation used to be an afterthought of software delivery. Now it is a key component of the success of a software project. Content strategy Originally it is a marketing term. Which is fine, as documentation is an important part of your project's marketing! The core is asking the right questions (even is the answer is simple). Who are my readers? Sounds like a simple question. But... are your readers advanced users? Or beginners? Do you need "persona-based" documentation, so documentation for specific groups ("admins", "developers", etc)? What do my readers want to know? Often your readers need context before they can understand reference documentation. Do you need an end-to-end tutorial? Or just explanations? Does the textual content need to be enhanced with video or diagrams, for instance? When do my readers need the content? Installation documentation right at the beginning to get started? A reference guide when you're already working with it? Tutorials for learning it? "When" also relates to "when do I need/want to update the documentation?" Where do my readers consume the content? Do you need a "man" page? Embedded help in your … -
Django under the hood: expressions - Josh Smeaton
(One of my summaries of a talk at the 2015 django under the hood conference). Josh Smeaton is a django core developer after his work on expressions. What already existed for a long time in django are F expressions. There are used to send a computation to the database. A self-contained parcel of SQL. Like "take the price field and add the shipping costs to it". Later aggregations were added. It is a bit the same, as it is "just a bit of sql" that gets send to the database. Expressions in django are now much more refined. Multiple database backend support. Deep integration in the ORM to make writing expressions yourself in django easier. It almost makes .extra() and .raw() obsolete. .raw() is for writing an entire query in SQL. For those corner cases where you need to do weird tricks that the ORM doesn't support. .extra() is for appending bits of SQL to the rest of your django query. It is evil and should go away. Both are escape hatches that are hardly ever needed. One problem with them is that they are database backend specific. Some examples of where you can use expressions: .create(... username=Lower(username)) .annotate(tital=F('price') + … -
Django under the hood: documentation systems - Eric Holscher
(One of my summaries of a talk at the 2015 django under the hood conference). Note by Reinout: I hope all the examples are rendered OK as I'm writing this blog with... sphinx and restructured text :-) Eric Holscher started https://readthedocs.org/ a few years ago during a "django dash" weekend. That site is widely used and even gave rise to "write the docs" conferences and a community around technical writing. Readthedocs and also the django documentation uses sphinx. A documentation system? It is not just a single documentation page on one item. It is documentation for a whole project. Sphinx extends RST (restructured text) with additions for documenting software. It also adds semantic meaning. Lot of documentation is written in markdown nowadays. A link to pep8 in markdown would be a simple link to pep8 on the internet. In sphinx/rst it could be: Check out :pep:`8` He becomes sad if he sees documentation written in markdown. "Read the docs" is build on "sphinx" is build on "docutils" is build on "restructured text". Here are some of the internal concepts of RST: A reader reads input. A parser takes the input and actually turns it into a "Doctree". RST is the … -
Django under the hood: Django security - Florian Apolloner
(One of my summaries of a talk at the 2015 django under the hood conference). Florian Apolloner talks about django security. Django security, so it won't be about attacks against the SSL protocol as those are outside of django. (But do look at https://www.ssllabs.com/ssltest/). In case you think you've found a security bug in django: look at https://djangoproject.com/security and only contact security@djangoproject.com. Don't report such a bug publicly, as that makes it much harder to make and distribute a proper fix. Regarding security: look at the owasp top 10 list of the most common found vulnerabilities in websites. SQL/SMTP/OS injections Basic rule: don't ever trust user input. Everything the user can input into your web interface is to be treated as dangerous. select * from auth_user where username=%s is easy to exploit if you inject a username string inputted by the user directly. If you use django, you don't run much risk as django does the good thing internally regarding escaping. Defense in layers is best. If you limit the parameter to an integer in your url patterns and select users by id instead of a string, you already prevent many problems. The same goes for OS interaction. Use Django …
