excepthook(type, value, traceback)
This function prints out a given traceback and exception to
sys.stderr.
When an exception is raised and uncaught, the interpreter calls
sys.excepthook with three arguments, the exception
class, exception instance, and a traceback object. In an
interactive session this happens just before control is returned to
the prompt; in a Python program this happens just before the
program exits. The handling of such top-level exceptions can be
customized by assigning another three-argument function to
sys.excepthook.