Taking over when exception occurs

class ExceptionHook :
    instance = None

    def __call__(self, *args, **kwargs) :
        if self.instance is None:
            from IPython.core import ultratb
            self.instance = ultratb.FormattedTB(mode = "Plain", color_scheme = "Linux", call_pdb = 1)
        return self.instance(*args, **kwargs)

import sys
sys.exceptionhook = ExceptionHook()