How can an Exception pass over an "except" clause ?

[Nebur]

> However by being *VERY* perverse, I was able to reproduce the above
> error by overwriting AttributeError with some other exception class (say
> SyntaxError):
>     AttributeError = SyntaxError
> Then your code will be will produce a real AttributeError, but miss it
> because (despite the spelling) it checks for a SyntaxError,

Yes ... this would be some kind of criminal joke

>
> Question...  I don't know what contract.py is, but could it be doing
> something that *bad*?

No. I've searched the source for "AttributeError" and it appears only
in except clauses.
contracty.py is a library that adds Eiffel-like "design-by-
contract" (DBC) to Python. Precisely, I can add preconditions (and
postconditions) about the arguments into the methods docstring. These
are checked at runtime (and appear in the epydoc docu.) This is a
great thing I never want to miss anymore (and it was working fine for
some months now.)
(See http://www.wayforward.net/pycontract/ )
When the problem appears, contract.py is doing a pre-condition check.

> You could check py printing AttributeError and see what it really is.
> In my case it's:
>     >>> print AttributeError
>     exceptions.SyntaxError
>
> Gary Herron
>
> P.S.:  Anyone who does this kind of thing is a danger to society.  May
> their finger fall off before they get a chance to distribute such a program.
:-)

@Tijs: I think when re-raising, the backtrace will always point to the
line where it was re-raised but not to line 1265. (Or can we re-raise
an exception so that it preserves the backtrace of the "original"
exception?)

---
I'm speculating about there's a misleading backtrace. Maybe another
exception happens, but somehow using the obsolete exc_info of the last
exception (the AttributeError). I remember about some way to clear the
exc_info, maybe this must be added into contract.py? I'll find it out,
or a debugger session this night will help (I'll post again)
 Ruben