ExpectPy
An extension for a Python-feel to the Expect library. [Open Source, LGPL]

Grouch
A system for describing and enforcing a Python object schema. [Open Source, Python license]

log4p
The Logging Toolkit For Python, modeled after the Java toolkit log4j. [Open Source, IBM Public License]

mxBase package extensions for Python
The eGenix.com mx Extensions for Python are a collection of professional quality Python software tools which enhance Python's usability in many important areas such as ODBC database connectivity, fast text processing, date/time processing and web site programming.

Orange
A free, component-based, public domain data mining software, which includes a range of preprocessing, modelling and data exploration techniques. [Open Source, GPL]

Pexpect
A pure Python module for spawning child applications; controlling them; and responding to expected patterns in their output. It works like Don Libes' Expect. [Open source, Python Software Foundation License]

pytables
A hierarchical database package designed to efficiently manage very large amounts of data. [Open Source, BSD]

Sisyphus
A module that simplifies running Python stuff as cron jobs. [Open Source, Python license]

The Snack Sound Toolkit
Module for basic sound handling (sound card and disk I/O); includes primitives for sound visualization, e.g. waveforms and spectrograms. [Open Source, GPL]

txObject ATK
Contains the following parts: Object Library, IO/Timers, Threads, Inter-Process/Distributed Communication. [Open Source, GPL]

Universal Serial Port Python Library
A multi-platform pure-Python module to access serial ports, which currently works on Linux and Windows. [Open Source, GPL]