Latest blog posts

Where I write about things like Python, Django, JavaScript and Linux.

Mara - a Python network service framework

I've released a new version of Mara, my network service framework written in Python. It aims to make it easy to build TCP/IP services, such as echo servers, flash policy servers, chatrooms, talkers and MUDs.

It's event-based; that is to say you write event listener functions which you bind to events that your service raises - like Connect, Receive or Disconnect.

Mara is on pypi, so you can pip install mara, then start writing your service. An echo server in Mara looks like this:

from mara import Service
service = Service()

def receive(event ...

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Introducing Tagulous

Tagulous is a tagging library for Django which is based on ManyToManyField and ForeignKey relationships. I've been developing and using it internally for several years, and have recently tidied it up for release; it supports Django 1.4 to 1.9a, on Python 2.7 to 3.5.

It started with a simple enough idea - rather than use generic relations like other tagging libraries, use a subclass of ManyToManyField which supports assignment using tag strings, to allow things like this:

class Person(models.Model):
  name = models.CharField(max_length=255)
  skills = TagField()

person = Person.objects.create(name='Bob', skills='run ...

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A Tiny Web Font Loader

Today I'm releasing TinyWFL, my tiny web font loader which is about 95% smaller than other popular loaders.

When web fonts started to gain adoption around 2010, the problem people had was FOUT - the flash of unstyled text while you waited for the browser to download the font. I think most people would agree that this has since been solved very comprehensively by webfontloader from Google and Typekit, and that it's now the de-facto standard loader - but back in 2010 or 2011 FOUT was still an issue, which is why I wrote my own.

To be accurate, my ...

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Tips for SSL certificates

Display CSR information:

openssl req -text -noout -in foo.csr

Display signed cert information:

openssl x509 -in foo.crt.pem -noout -text

To remove a password from a key:

openssl rsa -in foo.key.pem -out foo-unlocked.key.pem

To decode a CRL:

openssl crl -text -in ca.crl.pem

To check a certificate against a CRL:

cat ca/ca.crl.pem ca/ca.crt.pem > crl-check.pem
openssl verify -CAfile crl-check.pem -crl_check foo.crt.pem

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