I'm not sure about the accepted standard, but I found SOAPpy to be a pretty direct and useful library for handling SOAP services.
SOAPy is the SOAP / XML Schema library for Python. When using a WSDL or SDL document, SOAPy detects the published API for the web service and exposes it to Python applications as transparent as possible.
IBM provides a good passage and example on its website to get started with SOAPpy.
SOAPpy , ZOLERA SOAP (ZSI) Python Web Services Project. alos .