"assert" annoyance

[Thomas Heller]

Paul Rubin schrieb:
> So I have some assert statements in my code to verify the absence of
> some "impossible" conditions.  They were useful in debugging and of
> course I left them in place for "real" runs of the program.  Umpteen
> hours into a run, an assertion failed, and of course since failure
> was "impossible", I didn't catch the exception so the whole program
> crashed.  I don't know what I'd have done with the exception anyway,
> since it would have had to be caught at an outer scope where the
> data I cared about was no longer around, or else I'd have had to
> predict in advance what I needed to examine and pass that as a
> an arg to the assert statement.
> 
> What I really want is for any assertion failure, anywhere in the
> program, to trap to the debugger WITHOUT blowing out of the scope
> where the failure happened, so I can examine the local frame.  That
> just seems natural, but I don't see an obvious way to do it.  Am I
> missing something?  I guess I could replace all the assertions with
> function calls that launch pdb, but why bother having an assert
> statement?

http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/65287

Thomas