Xapian is a fairly popular full-text indexing system (”Probabilistic Information Retrieval library”). It’s got Python bindings, but they’re not so fun to use. Xapwrap is a layer on top of these bindings which tries to simplify matters:

exarkun@boson:~/xapwrap-demo$ cat > a-m
animal
bongo
car
delicate
effigy
fantastic
gorilla
humble
internet
jump
kaleidoscope
laughter
massive
exarkun@boson:~/xapwrap-demo$ cat > n-z
noisy
octothorp
pie
quartz
restful
sate
turtle
umbrage
vorpal
winter
xylophone
yak
zoo
exarkun@boson:~/xapwrap-demo$ python
Python 2.4.2 (#2, Sep 30 2005, 21:19:01)
[GCC 4.0.2 20050808 (prerelease) (Ubuntu 4.0.1-4ubuntu8)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from xapwrap import index, document
>>> idx = index.Index(name='demo.db', create=True)
>>> idCounter = 1
>>> docIDs = {}
>>> for docName in 'a-m', 'n-z':
...     docIDs[idCounter] = docName
...     text = document.TextField(file(docName).read())
...     idx.index(document.Document(textFields=[text], uid=idCounter))
...     idCounter += 1
...
>>> res = idx.search('zoo')
>>> print res
[{'score': 100, 'uid': 2}]
>>> print docIDs[res['uid']]
n-z
>>> idx.search('animal')
[{'score': 100, 'uid': 1}]
>>>

Get the Xapwrap 0.3.0 release.