Craig Labenz

Mocking things in Python (and specifically, in Django)

SATURDAY APRIL 5 2014 testing django

Correctly mocking external entities in your unit tests is a bit tricky syntactically, and I have to look up the exact incantations to type every single time they're needed. Thus, I'll make a quick sales pitch about mocking, quickly explain it to the best of my current understanding, and end with a sequence of tricks to be updated as I learn more. In essence, it's my own personal cheat sheet, stored in an accessible location I'm unlikely to misplace.

Dynamic, Complex Lookups in Django

MONDAY FEBRUARY 10 2014 django

Everyone knows about Django's Q objects and how to chain them together for complex lookups. The syntax is straight forward.

results = MyModel.objects.filter(Q(key1="value1") | Q(key2="value2"))

That generates this unexciting SQL:

SELECT *
FROM `my_table`
WHERE (`my_table`.`key1` = "value1" OR `my_table`.`key2` = "value2")

But what happens when you have an unknown amount of filters?

How I Made the Django Admin Scale for Stik.com

WEDNESDAY JUNE 12 2013 mysql django big-data

At Stik.com, we're using Django to supply a RESTful interface to our database. Our support staff is also using its admin for simple ticket items. Fortunately for the business, but unfortunately for the Django admin, we have lots of tables with hundreds of millions of rows, and a few in the billions. We really didn't want to spend the time writing our own admin section for support staff, so the Django admin was a godsend... until we rolled it out to production and saw admin pages never respond ever. Read on to see what our problem was and how we fixed it.

The problem(s):

Large tables in InnoDB may not be able to even render their change_list view due to (possibly 2) expensive COUNT(*) queries. With tables of 100M+ records, this can take 15+ minutes to complete, even on fast servers.

Up and running with Django, MySQL, Apache2, and EC2 (Part 2)

SATURDAY MARCH 23 2013 django apache

Before we get started, I'm assuming you've mastered or completed the first part of the tutorial, your site code itself is complete, your virtual environment is functional in local development, and you have your domain name pointed the IP of the EC2 instance we just made. If any of these assumptions are false then you are probably getting ahead of yourself.

Up and running with Django, MySQL, Apache2, and EC2 (Part 1)

SATURDAY MARCH 23 2013 django apache

This is super fast and easy. Here we go:

Step 1: Literally the first step

Create and log into your http://aws.amazon.com account. Yadda yadda yadda.

Mountain Lion, MAMP, and Django 1.4

MONDAY JULY 30 2012 mysql django

First, allow me to make a few assumptions:

You're running Mac OS X 10.8.
You have MAMP 2.x installed (and this is preventing MySQL-python from installing).
You're going to run your Django site within a virtualenv (If you weren't planning on doing this, now's a great time to change your mind!).
You're tired of PHP and you want to use Django, but because of other projects are unable to remove MAMP and start fresh.

Why it's failing:

MySQL-python won't compile because it needs the MySQL headers which are not in the expected location under a MAMP install. Luckily, this isn't hard to remedy.