How to except the unexpected?

[Paul Rubin]

James Stroud <jstroud at ucla.edu> writes:
> > approach. Basically this is reverse engineering the interface from the
> > source at the time of writing the app.
> 
> This is using the source as documentation, there is no law against
> that.

That's completely bogus.  Undocumented interfaces in the library
source are allowed to change between Python versions and across Python
implementations.  If you write your application according to the
documented interfaces in the Python manual, it should not break when
someone upgrades to the next Python release.  You should not have to
depend on undocumented aspects of the Python implementation which
change out of sync with the application.

> How things are and how things should be have always been 2 entirely
> different things. See early books by Robert J. Ringer for a more
> complete discussion.

That's like saying programs shouldn't have bugs, but they often do
anyway.  It doesn't mean the bugs are a good thing or that they
shouldn't be fixed.