I do lament it! It's a shame that the only useful diagram is hidden in a C source file.
import exceptions print exceptions.__doc__[1109:]
Now, in addition, I lament the fact that we've got two disjointly developed sets of documentation, fighting over who can be called authoritative: doc strings and the HTML docs on the web. :-(
--Guido van Rossum (home page: http://www.python.org/%7Eguido/)