For development in python:
Update for 12.04:
Unity lens development with singlet has been integrated into quickly:
quickly create unity-lens <lens-name>
You might want to look at a very nice wrapper class developed by Michael Hall called singlet: https://launchpad.net/singlet
A simple hello world lens would look like this:
from singlet.lens import SingleScopeLens, IconViewCategory
from singlet.utils import run_lens
name = 'helloworld'
cat1 = IconViewCategory("Cat One", "stock_yet")
def search(self, phrase, results):
results.append('http://google.com/search?q=%s' % phrase,
phrase, phrase, '')
if __name__ == "__main__":
Which is a lot simpler and faster to write than the original library versions.