import traceback


def formatExcept(cls, error, trace):
    """
    Formats the inputted class, error, and traceback information to the standard
    output commonly found in Python interpreters.
    
    :param      cls     | <type>
                error   | <str>
                trace   | <traceback>
    
    :return     <str>
    """
    clsname = cls.__name__ if cls else 'UnknownError'
    tb = 'Traceback (most recent call last):\n'
    tb += ''.join(traceback.format_tb(trace))
    tb += '{0}: {1}'.format(clsname, error)
    return tb