Turns out Python has had a wonderful zip library in its standard library since 1.6! The zipfile module makes creating zip files a breeze:

import os
from zipfile import ZipFile, ZIP_DEFLATED
 
from django.template.defaultfilters import slugify
 
from somewhere_else import render_spam_xml, render_egg_xml
 
ZIP_PATH = "/some/system/path/for/zips"
 
def create_zip(spam):
    spam_slug = slugify(spam.name)
    filename = "%s.zip" % spam_slug
    abspath = os.path.join(ZIP_PATH, filename)
 
    # Create zip
    z = ZipFile(abspath, "w", ZIP_DEFLATED)
 
    # Write spam xml directly to zip
    z.writestr("%s.xml" % spam_slug, render_spam_xml(spam))
 
    # Write xml files to zip
    for egg in spam.egg_set.all():
        egg_slug = slugify(egg.name)
 
        # Renders the egg object to an xml string
        xml = render_egg_xml(egg)
 
        # Note how easy it is to specify paths in the zip file:
        z.writestr("eggs/%s.xml" % egg_slug, xml)
 
    # Zip file must be closed to be valid
    z.close()
    return abspath

(Sorry for the Django bits in there, but they should be easy to replace.)

My favorite part is that you can use either the ZipFile.write method to add files to the zip or the ZipFile.writestr method to write bytes (strings in my case) directly to the zip file.

At any rate, just wanted to blog about it, so when I need to do it again in a few years I don’t do something stupid like running the zip command.

While I prefer Bazaar out of all the DVCSes, it seems Mercurial has captured the hearts and minds of the Python empire, so I created the python-fusioncharts project on BitBucket.

If you use Python and FusionCharts, I’d love to add more snippets!

Introduction to Django: The Who, What, and When

As with my other talk, Web Server Shootout, I’m not trying to convince anyone of anything. We’re all already inundated with plenty of senseless marketing and fanboyism.

I’d rather present my knowledge, experiences, mistakes, and opinions in an effort to help others make more intelligent decisions about the development platforms they choose to use.*

Let me know what you think!

*If that was dripping with too much sappy altruism, do remember I get into the conference free if either proposal gets selected.

Here’s my lightly modified version of Eric’s script:

import wsgiserver
import sys
import os
import django.core.handlers.wsgi
 
if __name__ == "__main__":
    # Setup paths - a bit hackish, but works for me.
    # Assumes an absolute path is stored in <project>.local_settings.ROOT
    sys.path.append(os.path.realpath(os.path.dirname(__file__)))
    from foo.local_settings import ROOT
    sys.path.append(ROOT)
 
    # Startup Django
    os.environ['DJANGO_SETTINGS_MODULE'] = 'foo.settings'
    server = wsgiserver.CherryPyWSGIServer(
        ('0.0.0.0', 8888),  # Use '127.0.0.1' to only bind to the localhost
        django.core.handlers.wsgi.WSGIHandler()
    )
    try:
        server.start()
    except KeyboardInterrupt:
        print 'Stopping'
        server.stop()

I also went with the latest stable version of CherryPy’s wsgiserver instead of checking out trunk like Eric’s post suggested.

Then I just enabled mod_proxy in Apache and setup the following VirtualHost:

<Proxy *>
    Order allow,deny
    Allow from all
</Proxy>
<Location "/">
    ProxyPass http://127.0.0.1:8888/
    ProxyPassReverse http://127.0.0.1:8888/
</Location>

If you’re cool you’ll write some sort of system specific script to launch your web app on boot. In a pinch, you can always use a crontab:

@reboot /usr/bin/python /path/to/app.py &

YMMV

* To mod_wsgi’s credit, it took about 10 seconds to compile, generated a Universal binary, and in general Just Worked.

** I’m already a CherryPy fan thanks to dowski, so it wasn’t a hard decision.

Update: Sorry about the tacky donate link all. I tried to hide it from feed readers with WordPress’s <!–more> feature, but evidently that doesn’t apply to feeds.

When it comes to market share, Google is to Searching as Microsoft is to Operating Systems. Thankfully Google has won their dominant position by creating a really amazing product (you can find plenty of discussions on why Microsoft is on top elsewhere).

Recently Yahoo! opened up their search APIs for anyone to use along with a handy Python library. In a time when Yahoo’s very existence is being threatened, I felt a pang of nostalgia for the search engine that fed me decent results for “free dos games” throughout the mid-90s.

So last night I whipped up a little search engine called Hzzah!*

Features:

• Simple
• No ads, cookies, or even JavaScript (at the moment at least)
• Open Source! BSD to be precise.
• Did I mention simple? That’s really all it has going for it…

If you have Bazaar installed you can grab the code a variety of ways:

# If you know Subversion, use this method.  `bzr up` will keep you up to date
bzr checkout http://michael.susens-schurter.com/code/hzzah-public
 
# If you want to hack on Hzzah or are comfortable with bzr, feel free to branch
bzr branch http://michael.susens-schurter.com/code/hzzah-public hzzah-steve

You can also grab a zip, but its probably going to become out of date quickly.

Read the README file for help setting it up.

And like I say in the README, if you’re feeling generous, feel free to toss some cash this way:

* Make fun of the name all you like… there’s no good domain names left. The name is inspired by a friend from college for whom huzzah was her exclamation of choice.

ImproperlyConfigured: Error while importing URLconf 'proj.app.urls': 'tuple' object is not callable

…you’re probably missing a comma in your URL configuration as Rajesh Dhawan pointed out.

Django pros can move along, I know you never make typos.