Django community: RSS
This page, updated regularly, aggregates Community blog posts from the Django community.
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Preliminary Django 1.9 support
Work is underway to make django-fluent compatible with Django 1.9. The following packages have been upgraded to support Django 1.9: django-fluent-blogs django-fluent-contents django-fluent-comments django-fluent-dashboard django-any-urlfield django-parler django-polymorphic (with the exception of the admin) django-polymorphic-tree django-slug-preview Work for django-fluent-pages is still underway. A 1.0b1 release is issued for testing. However, it does have issues with the admin and page moving that still need to be fixed. If you can help, please join in! New features A slug preview field, that shows which part of the URL will get the slug. blogs: support for django-categories-i18n, as replacement for django-categories. pages: translations for the textfile pagetype. pages: multiple fallback languages in URLs. pages: draft CSS class in the menu, and "is_child_active" variable for templates. contents: text-filters, to perform post-processing filters on textual content (e.g. apply smartypants, add soft-hyphenation). contents: API for search engine integration. contents: a debug toolbar panel for locating content. -
Hosting Django Application with Nginx and UWSGI
Setting up Django: Django is a python based web- application development framework. Setting up a sample app and running it as easy as pie. In here we will use 1. VIRTUALENV: a tool to create isolated Python environments. If it is not previously installed you can install it using sudo apt-get install python-virtualenv 2. PIP: a tool for installing python packages which if not previously available can be installed using sudo apt-get install python-pip Since we now have all the required packages for creating a Django Application. we need to Create Virtualenv virtualenv [virtualenv-name] Activate the virtualenv and install Django in it source /bin/activate pip install django Start a Django project django-admin.py startproject Deploying your sample Project: navigate into the project and you can find manage.py file. There you need to execute python manage.py runserver IP-Address and Port are not mandatory and by default, it runs on 127.0.0.1:8000 if you open http://127.0.0.1:8000 in a browser you will have Django welcome page which is enough for our deployment Installing Nginx: Nginx is a web server and like every other web server, it has it Pros and Con's. Nginx was an answer to concurrency issue(handling thousands of concurrent connections) faced in apache and raised to fame. … -
A Python Solution for Making Custom PDFs from HTML
A Python Solution for Making Custom PDFs from HTML -
Reflecting on My Time as Caktus' Open Source Fellow
My name is Ben Phillips and I am Caktus’ Open Source Fellow. As my fellowship comes to a close, I wanted to reflect on my time at Caktus and to share my experience and some of what I’ve learned here. First, however, I should probably share how I ended up here in the first place. -
"Complex" and "complicated"
I'm not a native english speaker, so sometimes I need to refresh my memory as to the exact meaning of a word. In this case the exact difference between complex and complicated. I found an english.stackexchange.com page with some nice answers. According to the first answer: Complex is about the number of parts. The more (different) parts, the more complex. Complicated is about how hard/difficult something is. Another answer pointed at the relevant part of the Zen of Python: Simple is better than complex. Complex is better than complicated. So when programming, you can divide up a task or problem into separate parts. The more parts, the more complex. Simple is better than complex, so don't add too many parts if you don't need them. On the other hand, if you want to do everything in one part, it might end up being too difficult, too complicated. Making it more complex (more parts) is better in that case. It is a trade-off. And it takes experience and a bit of Fingerspitzengefühl to make the right trade-off. How to learn it? Talk with more experienced programmers is one way. Another way is to explicitly review your programs yourself with those two … -
Useful commands for PostgreSQL
Some useful PostgreSQL commands that I need from time to time. Execute with postgres user. List all users psql \du Remove a user dropuser USERNAME List all databases psql \list Remove a database dropdb DATABASENAME; Update password of user psql alter user USERNAME with password 'NEWPASSWORD'; Create a database and user, assign user to database createuser -P USERNAME createdb -O USERNAME DATABASENAME Remove all tables of a schema (if all tables in a single schema) drop schema public cascade; create schema public; -
A summary of a year
As 2015 is slowly drawing to an end, I looked back through Evennia's repository to see just what was going on this year. And it turns out it was a lot! I honestly didn't remember some things happened as recently as they did.Note: For those reading this not familiar with Evennia, it's a Python library for creating MUDs (text-based multiplayer games). Making Evennia into a libraryIn February of 2015 we merged what was likely the biggest change happening for a good while in Evennia - the complete refactoring of the Evennia repository into a library. It used to be that when you cloned the Evennia repo, it would come with a pre-made game/ folder where you were supposed to put your custom files. Mixing the stuff you downloaded from us with your own files (which you might want to keep under version control of your own) was not a very clean solution.In the big "library update", we instead created a stand-alone evennia program which you use to create your own "game dir" with pre-created templates. Not only does this allow you to treat the cloned evennia repo as a proper library, you can also use the same evennia install for … -
Caktus CTO Colin Copeland Helps Launch Open Data Policing Website
Today, at Caktus headquarters, CTO and co-founder of Caktus Colin Copeland will stand at a press conference along with activists, police representatives, and elected officials to announce the launch of OpenDataPolicingNC.com. The first site of its kind, OpenDataPolicingNC.com draws on public records to publish up-to-date stop, search, and use-of-force data—broken down by race and ethnicity—for every police department and officer in the state of North Carolina. The volunteer effort, led by The Southern Coalition for Social Justice (SCSJ) and technical leadership by Colin, includes approximately 20 million anonymized data points from 15 years of NC traffic stop data. -
Launching Jazzband
We are all part of the band. Jazzband is a cooperative experiment to reduce the stress of maintaining Open Source software projects. It aims at lowering the barrier of entrance for people willing to step up as maintainers and grants access to GitHub repositories hosted under the Jazzband GitHub organization to everyone who joins. It’s supposed to simplify the process of managing a volunteer project for the original author(s) and makes stepping away easier. Its purpose can most easily be characterized as “relief”: Relief from the exhausting parts of being a maintainer — either of big or small software projects, widely used or only written for one task. Relief of not knowing how to get a fix landed or a feature added as a user. It normalizes the relationship between creators and consumers, between “core committers” and “end users”. There are a few guidelines to follow before deciding to transfer existing projects to the Jazzband or creating a new one like agreeing to the Jazzband’s code of conduct. Some optional features should also be considered to be used by the Jazzband projects to further improve the contribution workflow. I guess some band members will want to take the lead singer … -
slugify() for postgres (almost)
A recent discussion in #django suggested "what we need is a PG slugify function". The actual algorithm in Django for this is fairly simple, and easy to follow. Shouldn't be too hard to write it in SQL. Function `slugify(value, allow_unicode=False)`. * Convert to ASCII if `allow_unicode` is false * Remove characters that aren't alphanum, underscores, hyphens * Strip leading/trailing whitespace * Convert to lowercase * Convert spaces to hyphens * Remove repeated hyphens (As an aside, the comment in the django function is slightly misleading: if you followed the algorithm there, you'd get a different result with respect to leading trailing whitespace. I shall submit a PR). We can write an SQL function that uses the Postgres `unaccent` extension to get pretty close: {% highlight postgresql %} CREATE OR REPLACE FUNCTION slugify("value" TEXT, "allow_unicode" BOOLEAN) RETURNS TEXT AS $$ WITH "normalized" AS ( SELECT CASE WHEN "allow_unicode" THEN "value" ELSE unaccent("value") END AS "value" ), "remove_chars" AS ( SELECT regexp_replace("value", E'[^\w\s-]', '', 'gi') AS "value" FROM "normalized" ), "lowercase" AS ( SELECT lower("value") AS "value" FROM "remove_chars" ), "trimmed" AS ( SELECT trim("value") AS "value" FROM "lowercase" ), "hyphenated" AS ( SELECT regexp_replace("value", E'[-\s]+', '-', 'gi') AS "value" FROM "trimmed" … -
Improving page speed score in Google Page Score test- PART1
About PageSpeed Insights: Google's Page Speed Insights measures the performance of a page for mobile devices and desktop devices. It fetches the url twice, once with a mobile user-agent, and once with a desktop-user agent. The PageSpeed Score ranges from 0 to 100 points. A higher score is better and a score of 85 or above indicates that the page is performing well. Please note that PageSpeed Insights is being continually improved and so the score will change as we add new rules or improve our analysis. PageSpeed Insights measures how the page can improve its performance on: time to above-the-fold load: Elapsed time from the moment a user requests a new page and to the moment the above-the-fold content is rendered by the browser. time to full page load: Elapsed time from the moment a user requests a new page to the moment the page is fully rendered by the browser. 1. time to above-the-fold-load: Above the fold content is some thing that appears on screen's worth, anything that you don't scroll. This is completely related to Designing part, so we'll not concentrate on this in this post. 2. time to full page load: Time to full page load depend upon … -
Celery With Supervisor
Celery: Celery is a task queue with focus on real-time processing,while also supports task scheduling. Task queues are used as mechanisms to distribute work across multiple threads or machines. A task queues input is a unit of work called a task,dedicated worker processes and constantly moniter the queue for new work to perform. Celery communicates via messages using a broker to mediate between workers and clients.To initiate a task client puts a message on the queue, then the broker delivers that message to a worker. Note: You can get more about celery http://celery.readthedocs.org/en/latest/django/first-steps-with-django.html To run celery in virtual environment need to type the following command in your virtual environment export C_FORCE_ROOT="true" Running the worker with supervisor In production you will want to run the worker in the background as a daemon and some times there may be a chance of stopping of celery worker automatically then it should be restarted automatically. To do thes tasks you need to use the tools provided like supervisord. First, you need to install supervisor in your virtualenv and generate a configuration file. $ pip install supervisor $ cd /path/to/your/project $ echo_supervisord_conf > supervisord.conf Next, just add the following section in configuration file: … -
Preserve file names with sorl for better SEO
We use sorl-thumbnail for scaling images by keeping the original one intact. Sorl proven to be a great tool for generating different sized images throughout the website. I presume that you know how to use sorl-thumbnail. Here we see how to preserve filename. Search Engines will give importance to image alt tag content but it definitely has some impact on relevant image file name too. Sorl will generate random names for the thumbnails it will create and as of now, there is no default setting to preserve filename in generating thumbnails. It is possible to have the same name for different sized images as sorl will create thumbnails in random folders, so, there will be no conflict in names. Here is the way to achieve that: We must override the thumbnail backend. So provide THUMBNAIL_BACKEND=’SEOThumbnailBackend’ Now we should create the class that returns our custom filenames. # thumbnailname.py from sorl.thumbnail.base import ThumbnailBackend, EXTENSIONS from sorl.thumbnail.conf import settings from sorl.thumbnail.helpers import tokey, serialize import os.path class SEOThumbnailBackend(ThumbnailBackend): def _get_thumbnail_filename(self, source, geometry_string, options): """ Computes the destination filename. """ key = tokey(source.key, geometry_string, serialize(options)) filename, _ext = os.path.splitext(os.path.basename(source.name)) path = '%s/%s' % (key, filename) return '%s%s.%s' % (settings.THUMBNAIL_PREFIX, path, EXTENSIONS[options['format']]) It’s important … -
Useful commands for MySQL
Some useful MySQL commands that I need from time to time: MySQL List all users select User, Host from mysql.user; Remove a user show grants for 'USERNAME'@'localhost'; revoke all privileges, grant option from 'USERNAME'@'localhost'; drop user 'USERNAME'@'localhost'; List all databases show databases; Remove a database drop database DATABASENAME; Update password of user update mysql.user set password=PASSWORD("NEWPASSWORD") where User = 'USERNAME'; flush privileges; Create a database and user, assign user to database create database DATABASE defaukt character set utf8 collate utf8_general_ci; grant all on DATABASE.* to 'USERNAME'@'localhost' identified by 'PASSWORD'; flush privileges; -
Faster Django Sites with PyPy
This post was created as a collaboration between Lincoln Loop and Maciej Fijalkowski from baroquesoftware.com. In the space of web architecture, the prevalent belief states that "database based applications are I/O bound". While this might have been true in the past, two developments have highly encroached on that. First, memory has been getting bigger and bigger—minimizing the need to access the HD. Second, the database connection layers have been getting increasingly sophisticated—putting more and more pressure on the CPU. For CPU bound Python applications, using PyPy instead of the traditional CPython interpreter can provide massive improvements (5x or more is common). In this post we examine how PyPy can improve the Django ORM's execution times. We built a set of benchmarks using some "simple" queries with the Django ORM. These let us analyze PyPy's performance and warmup stats. Finally, we want to present some future developments to improve the current situation. Let's start with the benchmark description - it's a simple set of queries that were distilled from the BotBot IRC logging system. The original source can be found on GitHub. There is really nothing fancy, just a series of queries to a SQLite database. BotBot uses Postgres in production, … -
Encrypted Postgres Backups
Encrypted Postgres Backups -
Why you should use the Django admin: 9 tips
This writing is inspired by a comment on Reddit concerning my recent post: “The problem is that everyone I speak to seems to think the opposite - that the admin is super-limited, inflexible and hard to customize.” — andybak on Reddit I’m about to break this prejudice right now. The Django admin is a really brilliant piece of software, which can significantly speed up your development. Here are some tips about the Django admin, which I’ve found to be quite useful. -
Why you should use the Django admin: 9 tips
This writing is inspired by a comment on Reddit concerning my recent post: “The problem is that everyone I speak to seems to think the opposite - that the admin is super-limited, inflexible and hard to customize.” — andybak on Reddit I’m about to break this prejudice right now. The Django admin is a really brilliant piece of software, which can significantly speed up your development. Here are some tips about the Django admin, which I’ve found to be quite useful. -
Automatic Maintenance Page for Nginx+Django app
If you've used Django with Nginx, you are probably familiar with how to configure the Nginx process group to reverse proxy to a second Gunicorn or uWSGI Django process group. (The proxy_pass Nginx parameter passes traffic through Nginx to Django.)One benefit of this approach is that if your Django process crashes or if you are preforming an upgrade and take Django offline, Nginx can still be available to serve static content and offer some sort of "the system is down" message to users. With just a few lines of configuration, Nginx can be set to automatically display a splash page in the above scenarios.If the Django process running behind the reverse proxy becomes unavailable, a 502 error will be emitted by Nginx. By default, that 502 will be returned to the browser as an ugly error message. However, Nginx can be configured to catch that 502 error and respond with custom behavior. Specifically, if a 502 is raised by Nginx, Nginx can check for a custom html error page document and serve up that document if it exists. If that document does not exist, Nginx can just return the default ugly 502 error message. The Nginx configuration below executes this … -
Row Level Security in Postgres and Django
Postgres keeps introducing new things that pique my attention. One of the latest ones of these is [Row Level Permissions](http://www.postgresql.org/docs/devel/static/ddl-rowsecurity.html), which essentially hides rows that a given database user cannot view. There's a bit more to it than that, a good writeup is at [Postgres 9.5 feature highlight: Row-Level Security and Policies](http://michael.otacoo.com/postgresql-2/postgres-9-5-feature-highlight-row-level-security/). However, it's worth noting that the way Django connects to a database uses a single database user. Indeed, if your users table is in your database, then you'll need some way to connect to it to authenticate. I haven't come up with a nice way to use the Postgres users for authentication within Django just yet. I did have an idea about a workflow that may just work. * Single Postgres User is used for authentication (Login User). * Every Django user gets an associated Postgres User (Session User), that may not log in. * This Session User is automatically created using a Postgres trigger, whenever the Django users table is updated. * After authentication, a `SET SESSION ROLE` (or `SET SESSION AUTHORIZATION`) statement is used to change to the correct Session User for the remainder of the session. Then, we can implement the Postgres Row Level Security … -
reverse, lazy and resolve - Django url-resolvers
Working with urls is a core part of web development. The url-resolver utilities django provides makes working with them just that much easier. Look at using `reverse`, `reverse_lazy`, and `resolve` utility functions to write better idiomatic django.Watch Now... -
Headsupper.io
tl;dr Headsupper.io is a free GitHub webhook service that emails people when commits have the configurable keyword "headsup" in it. Introduction Headsupper.io is great for when you have a GitHub project with multiple people working on it and when you make a commit you want to notify other people by email. Basically, you set up a GitHub Webhook, on pushes, to push to https://headsupper.io and then it'll parse the incoming push and its commits and look for certain things in the commit message. By default, it'll look for the word "headsup". For example, a git commit message might look like this: fixes #123 - more juice in the Saab headsup! will require updating Or you can use the multi-line approach where the first line is short and sweat and after the break a bit more elaborate: bug 1234567 - tea kettle upgrade 2.1 Headsup: Next time you git pull from master, remember to run peep install on the requirements.txt file since this commit introduces a bunch of crazt dependency changes. Git commits that come through that don't have any match on this word will simply be ignored by Headsupper. How you use it Maybe paradoxically, you need to authenticate with … -
Headsupper.io
tl;dr Headsupper.io is a free GitHub webhook service that emails people when commits have the configurable keyword "headsup" in it. Introduction Headsupper.io is great for when you have a GitHub project with multiple people working on it and when you make a commit you want to notify other people by email. Basically, you set up a GitHub Webhook, on pushes, to push to https://headsupper.io and then it'll parse the incoming push and its commits and look for certain things in the commit message. By default, it'll look for the word "headsup". For example, a git commit message might look like this: fixes #123 - more juice in the Saab headsup! will require updating Or you can use the multi-line approach where the first line is short and sweat and after the break a bit more elaborate: bug 1234567 - tea kettle upgrade 2.1 Headsup: Next time you git pull from master, remember to run peep install on the requirements.txt file since this commit introduces a bunch of crazt dependency changes. Git commits that come through that don't have any match on this word will simply be ignored by Headsupper. How you use it Maybe paradoxically, you need to authenticate with … -
Django forms and making datetime inputs localized
tl;dr To change from one timezone aware datetime to another, turn it into a naive datetime and then use pytz's localize() method to convert it back to the timezone you want it to be. Introduction Suppose you have a Django form where you allow people to enter a date, e.g. 2015-06-04 13:00. You have to save it timezone aware, because you have settings.USE_TZ on and it's just many times to store things in timezone aware dates. By default, if you have settings.USE_TZ and no timezone information is in the string that the django.form.fields.DateTimeField parses, it will use settings.TIME_ZONE and that timezone might be different from what it really should be. For example, in my case, I have an app where you can upload a CSV file full of information about events. These events belong to a venue which I have in the database. Every venue has a timezone, e.g. Europe/Berlin or US/Pacific. So if someone uploads a CSV file for the Berlin location 2015-06-04 13:00 means 13:00 o'clock in Berlin. I don't care where the server is hosted and what its settings.TIME_ZONE is. I need to make that input timezone aware specifically for Berlin/Europe. Examples Suppose you have settings.TIME_ZONE == … -
Django forms and making datetime inputs localized
tl;dr To change from one timezone aware datetime to another, turn it into a naive datetime and then use pytz's localize() method to convert it back to the timezone you want it to be. Introduction Suppose you have a Django form where you allow people to enter a date, e.g. 2015-06-04 13:00. You have to save it timezone aware, because you have settings.USE_TZ on and it's just many times to store things in timezone aware dates. By default, if you have settings.USE_TZ and no timezone information is in the string that the django.form.fields.DateTimeField parses, it will use settings.TIME_ZONE and that timezone might be different from what it really should be. For example, in my case, I have an app where you can upload a CSV file full of information about events. These events belong to a venue which I have in the database. Every venue has a timezone, e.g. Europe/Berlin or US/Pacific. So if someone uploads a CSV file for the Berlin location 2015-06-04 13:00 means 13:00 o'clock in Berlin. I don't care where the server is hosted and what its settings.TIME_ZONE is. I need to make that input timezone aware specifically for Berlin/Europe. Examples Suppose you have settings.TIME_ZONE == …
