The DispatcherKeyError class is accessible via the sqlobject.include.pydispatch.errors module.
<attribute 'args' of 'exceptions.BaseException' objects>
exception message
x.__getitem__(y) <==> x[y]
x.__getslice__(i, j) <==> x[i:j]
Use of negative indices is not supported.
x.__init__(...) initializes x; see x.__class__.__doc__ for signature
See the source for more information.