Paraphrasing the original (2.0) website:

  ZSI, the Zolera SOAP Infrastructure, is a Python package that provides an
  implementation of SOAP messaging, as described in The SOAP 1.1
  Specification. In particular, ZSI parses and generates SOAP messages, and
  converts between native Python datatypes and SOAP syntax.  ZSI, the Zolera
  SOAP Infrastructure, is a pure Python module that provides
  an implementation of the SOAP 1.1 specification. Simple client and server
  support are also provided.

WWW: http://pywebsvcs.sourceforge.net/