Comments in the documentation regarding the behaviour
on the Macintosh appear to be referring to the
behaviour under MacOS 9 and the behaviour under MacOS X
is different.

For example, the documentation (for at least 2.3.4 and
2.4) for os.path.expanduser states "On the Macintosh,
this always returns path unchanged."  Under MacOS X
(the example below is for 10.3.7) this is not true:

[ezri:~] jmfarrow% uname -a
Darwin ezri.internal 7.7.0 Darwin Kernel Version 7.7.0:
Sun Nov  7 16:06:51 PST 2004;
root:xnu/xnu-517.9.5.obj~1/RELEASE_PPC  Power Macintosh
powerpc
[ezri:~] jmfarrow% python
Python 2.3 (#1, Sep 13 2003, 00:49:11)
[GCC 3.3 20030304 (Apple Computer, Inc. build 1495)] on
darwin
Type "help", "copyright", "credits" or "license" for
more information.
>>> import os
>>> os.path.expanduser("~jmfarrow")
'/Users/jmfarrow'

Logged In: YES 
user_id=357491

You're right; "Machintosh" in the docs refer to MacOS 9 and not OS X.  
You can pretty much always view things in terms of UNIX for OS X.  
Should probably go through the docs and double-check all Macintosh 
references, perhaps even rename all "Macintosh" references to "darwin".

As for this specific case, fixed in rev. 1.41 for 2.5 and 1.40.2.1 for 2.4 .