I have installed Python 3.2 and the book is specifically titled for Python 2.6 and 3.1, so maybe the newer version doesn't support docstrings. Here is the error message I get when I invoke the print statement at the top of page 76:

>>> print("%s" % in_fridge._doc_)
Traceback (most recent call last):
File "<pyshell#5>", line 1, in <module>
print("%s" % in_fridge._doc_)
AttributeError: 'function' object has no attribute '_doc_'
>>>

Another unexpected behavior is that the triple quoted docstring in in_fridge() has to be indented or a get a syntax error window with the message
"expected an indented block"

As long as I indent the triple quoted string, the module runs. So far, Nothing I've tried will make the docstring feature work.

Somehow missed the authors note that there are two underscores preceding doc.