the newest version of Sphinx supports testing doctest (and other) snippets in the documentation. Since we have many examples in the docs that may get out of date, I think this is a valuable thing to have.
I've started making the doctests runnable with Sphinx in three documents; the functional howto, the RE and the Decimal docs.
If you want to know how to run the doctests, it should be as easy as
$ cd Doc $ make doctest PYTHON=../python
on UNIX. The PYTHON=../python is needed to really test against the tree version of Python, not the system-wide installed one.
If you want to run only tests in one source file, run
$ make doctest PYTHON=../python SOURCES=library/decimal.rst
If there is further interest in this, I'll explain the details how to "activate" examples to work with "make doctest".