I'd helped to train a bunch of people into Python for XSI over a range of time, so my advice would be with respect to the process of learning.
First learn Python. Then work on Python in the context of XSI. Why? It's important for you to understand the syntax and logic structure of Python as its own entity before you inject the idiosyncrasies of XSI, with ActiveX, and the Object Model. You want to review each data type in Python, learn about their built in methods, learn how to convert between them. During this process you will quickly come to realize how powerful Python is compared to VBscript, and how Python rewards you for being clever which makes it more fun to work with. The O'Reilly book on learning basic Python<http://www.amazon.com/Learning-Python-Edition-Mark-Lutz/dp/0596513984>is excellent for learning in this structure. >From personal experience, I had been tinkering with Python in XSI for about a year (after many years of coding in jscript) before I shifted into building a pipeline using a Python-based web development language that had nothing to do with XSI. It was only after my experience dealing with building custom data structures, and eventually messing around with the guts of Python to manipulate information at the core that I really developed an appreciation and love for the language, and ultimately progressed towards being a power user once back in XSI. -B
