What SOAP client libraries exist for Python, and where is the documentation for them?
Update (2016):
If you only need SOAP client, there is well maintained library called zeep. It supports both Python 2 and 3 :)
Update:
Additionally to what is mentioned above, I will refer to Python WebServices page which is always up-to-date with all actively maintained and recommended modules to SOAP and all other webservice types.
Unfortunately, at the moment, I don't think there is a "best" Python SOAP library. Each of the mainstream ones available has its own pros and cons.
Older libraries:
SOAPy: Was the "best," but no longer maintained. Does not work on Python 2.5+
ZSI: Very painful to use, and development is slow. Has a module called "SOAPpy", which is different than SOAPy (above).
"Newer" libraries:
SUDS: Very Pythonic, and easy to create WSDL-consuming SOAP clients. Creating SOAP servers is a little bit more difficult. (This package does not work with Python3. For Python3 see SUDS-py3)
SUDS-py3: The Python3 version of SUDS
spyne: Creating servers is easy, creating clients a little bit more challenging. Documentation is somewhat lacking.
ladon: Creating servers is much like in soaplib (using a decorator). Ladon exposes more interfaces than SOAP at the same time without extra user code needed.
pysimplesoap: very lightweight but useful for both client and server - includes a web2py server integration that ships with web2py.
- SOAPpy: Distinct from the abandoned SOAPpy that's hosted at the ZSI link above, this version was actually maintained until 2011, now it seems to be abandoned too.
- soaplib: Easy to use python library for writing and calling soap web services. Webservices written with soaplib are simple, lightweight, work well with other SOAP implementations, and can be deployed as WSGI applications.
- osa: A fast/slim easy to use SOAP python client library.
Of the above, I've only used SUDS personally, and I liked it a lot.
I followed the advice of other answers to this question and gave SUDS a try. After using it "in anger" I must agree: SUDS is very nice! Highly recommended!
I did run into trouble calling HTTPS-based web services from behind a proxy. At the time of this writing, this affects all Python web-service clients that use urllib2, so I'll document the solution here.
The urllib2 module shipping with python 2.6.2 and below will not issue a CONNECT to the proxy for HTTPS-over-HTTP-proxy sessions. This results in a long timeout, or if you are lucky, an error that looks like:
abort: error: error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol
This was issue1424152 on the Python bug tracker. There are patches attached to the bug report that will fix this in Python 2.x and Python 3.x. The issue is already fixed.
I had good experience with SUDS https://fedorahosted.org/suds
Used their TestSuite as documentation.