python – dave's blog of art and programming

Connecting Flask to Apache

When exploring the cosmos of python powered web frameworks it’s easy to get lost due to fast moving versions. Recently we had a lot of difficulty getting Flask connected via a WSGI script on Apache. This seems to be due to needing the object factory to be called specifically rather than relying on the module namespace to do the work for us, there doesn’t seem to be much help online about this yet. We’re also running python in a virtualenv so the working wsgi script looks like this:

#!/usr/bin/python                                                               
import sys
import logging
import os

logging.basicConfig(stream=sys.stderr)
PROJECT_DIR = "/var/www/yourflasksite/"
activate_this = os.path.join(PROJECT_DIR, 'bin', 'activate_this.py')
execfile(activate_this, dict(__file__=activate_this))

sys.path.append(PROJECT_DIR)
from app import create_app
application=create_app(os.getenv('FLASK_CONFIG') or 'default')
application.secret_key = 'your site's key'

For completeness, here is the apache config that starts it up:

<VirtualHost *:80>
    ServerName your.url
    WSGIScriptAlias / /var/www/yourflasksite/yoursite.wsgi
    <Directory /var/www/yourflasksite/app>
	Order allow,deny
        Allow from all
    </Directory>
    Alias /static /var/www/yourflasksite/app/static
    <Directory /var/www/yourflasksite/app/static/>
        Order allow,deny
        Allow from all
    </Directory>
    ErrorLog ${APACHE_LOG_DIR}/yourflasksite-error.log
    LogLevel warn
    CustomLog ${APACHE_LOG_DIR}/yourflasksite-access.log 
</VirtualHost>

Thoughts on teaching programming with Minecraft and Python

Saturday saw the first dBsCode taster workshop, for budding programmers between 11 and 16. We set up 20 Raspberry Pi’s, which we networked together and used our new procedural Minecraft 3D shape primitives to build a number of projects in Python involving castles, spiders and an infinite house generator.

Networking was very important – it enabled them to jump into each other’s games which started as a major distraction, but ended up being useful – as people could see what each other were doing and work together.

As part of this, some level of ‘griefing’ was present (where other players interfere in your world), but asking them about this during the breaks, the consensus was that this is part of the culture of Minecraft – I even instructed victims to pull their network cables out, but they saw that as completely unnecessary. Most of them took turns in both constructive/collaborative and programming activity and destructive/graffiti like activities associated with griefing, and this was acceptable to them. The use of code to easily rebuild structure after damage (or being able to remove people with liberal procedural application of lava) was therefore quite an attractive feature of the code approach.

It was common to adapt the programming to fit their understanding of Minecraft, so it seemed natural to take on a hybrid approach to building – using Python to do the heavy lifting (building, or extracting large areas) or repetitive tasks, after which they did the fiddly or more creative bits manually as normal. For example one student used the sphere primitive to extract huge caves underground, and then filled them with little hand made shrines and sculptures.

What was interesting was that to some extent the ‘experts’ at Minecraft (many of whom already document their creations on Youtube channels) found this more challenging in many ways than those less attached to the Minecraft culture – who were more accepting of new ways of doing things.

The manner of programming we used here – running Geany (a lightweight Python IDE) at the same time as Minecraft, was completely in line with livecoding practice, as programs interacted with the Minecraft world in realtime with network messages. The great thing about the rather slow network bottleneck is that you can walk around a structure while the program is creating it, which allows a much better understanding of how the process is working than if it instantly popped into existence.

Self replicating structures in Minecraft

A little gallery of accidents and broken experiments. All the code here.

A little island of original pristine environment in danger of being swamped:

More procedural Minecraft architecture

More work on the Python teaching environment we’ll be using next week for the Minecraft workshop at dBsMusic. I’m working on various ideas for procedural architecture, using this as a way to demonstrate what programming is about – thinking procedurally/functionally. The code is online here – I’ll be adding some exercises and course materials over the next few days.

Edit: Documentation on how to use, also install.sh should work on Raspberry Pi. Exercises to follow.

Strange terraforming

Working on the upcoming Raspberry Pi programming workshop for dBsCode, I’m wrapping the Minecraft Python API with a functional style one to reduce the amount of syntax we’ll have to teach. The idea is to build complex 3D shapes via abstraction, out of simple primitives.

The IDE we’re using is Geany which seems to run well alongside Minecraft on the Raspberry Pi so far. It’s great how Minecraft stays on top of the display at all times – more an unintentional feature of the GPU driver, but very useful for teaching.