Here is a list of known Python-based WikiEngines
Hatta -- a Wiki which runs out of a Mercurial repository whose pages are just the files in that repository
Markdoc -- a lightweight Markdown-based Wiki system, public domain
MoinMoin -- an evolution over PikiPiki that you're using now - multiple way to run, plugin-based architecture with lots of plugins and large community, GPL
MonkeyWiki -- Simple install/use, single file, very flexible templating, rewrite-friendly (based on PikiPiki)
Not-Yet-Named Wiki -- runs on Webware. Supports static publishing, WYSIWYG editing, ReStructuredText. Still in rapid initial development phase (as of Apr 2004).
PikiePikie -- Python-based, lets you put a WebLog on any page (based on PikiPiki)
PikiPiki -- Python-based, will run completely standalone
PyleWiki -- Python-based, optional CVS backend, Unix-like rwxrwxrwx permissions on pages
PyWiki -- Python-based, uses RCS, GPL license (development stalled)
Sphene Community Tools -- Django based wiki and forum applications.
Sycamore -- seems to have roots in MoinMoin, but looks a little slicker while not as full featured. Uses a Postgesql or MySQL backend. GPL
Trac -- an enhanced wiki and issue tracking system for software development projects. Supports MoinMoin-style, ReStructuredText, html, and textile as markup formats. Runs as cgi, FastCGI, ModPython, or with standalone server. Pluggable architecture with focus on simplicity.
WikiForNow -- an old ZwiKi variant; used at zope.org; was meant to get a number of improvements implemented quickly, but has not evolved with usage patterns
WikiNehesa -- Many features, including images, headerbars, TEXT centering, image inventory/previewer, image uploader. Modular. $FREE$. GNU GPL.
WyPy -- a ShortestWikiContest contender, 23-, 18-, and 11-line versions.
zim-wiki at http://www.zim-wiki.org -- WYSIWIG personal/desktop wiki with index, links, image inclusion, checkboxes and bulleted lists, equations, graphviz; calendar, ToDo; prints to clean html. Customizable, all-python over gtk2, inbuilt-server, uses filesystem as db; debian packaged. Documentation. Actively developed 2012.
Archaeology (dead, missing and outdated)
CyberPublishing -- a wiki-based web publishing framework written in Python; GPL
Luminotes -- a WYSIWYG personal wiki notebook for organizing your notes and ideas. Not currently developed.