YASS

The following Python libraries from AG-Projects offer SIP SIMPLE rich presence and XCAP implementation:

• http://sipsimpleclient.com/wiki/SipPresenceApi
• http://sipsimpleclient.com/wiki/SipXCAPApi

The following RFC's must be understood before it:

• RFC 3856 -- A Presence Event Package for SIP
• RFC 3857 -- A Watcher Information Event Template-Package for SIP (winfo)
• RFC 3858 -- An Extensible Markup Language (XML) Based Format for Watcher Information
• RFC 3863 -- PDIF: Presence Information Data Format
• RFC 4479 -- A Data Model for Presence
• RFC 4480 -- RPID: Rich Presence Extensions to the Presence Information Data Format
• RFC 4482 -- CIPID: Contact Information for the Presence Information Data Format
• RFC 4662 -- A SIP Event Notification Extension for Resource Lists
• RFC 4745 -- Common Policy: A Document Format for Expressing Privacy Preferences
• RFC 4825 -- XML Configuration Access Protocol (XCAP)
• RFC 4826 -- XML Formats for Representing Resource Lists
• RFC 4827 -- XCAP Usage for Manipulating Presence Document Contents
• RFC 5025 -- Presence Authorization Rules

Also, it's required to find a Python XML library implementing Xpath and XML namespaces (100% required, but note that many XML libraries don't implement XML namespaces at all).

Since I've alreayd read all these RFC's and I'm creating a XCAP client library (in Ruby) let me know when you are ready to start with it and I'll help you :)