How to access an MTP USB device with python

Calibre, a popular ebook management program, has python and C source code to transfer files over an MTP connection. http://code.google.com/p/calibre-ebook/downloads/list

One way to do this would be to install ADB (android debugging bridge, part of the SDK) and launch it as a child process from python. ADB can be used to, among other things, read from or write to, an android device.