def raiser_g(e):
    raise e
    yield 1

def g2():
    yield 1

def append_error(e):
    it = raiser_g(e)

    try:
        next(it)
    except:
        it2 = g2()
        next(it2)

    try:
        next(it2)
    except StopIteration:
        return

def main():
    append_error(RuntimeError("These exception objects are prepended"))
    append_error(RuntimeError("to the stack of chained errors"))

    raise ValueError("HAI WORLD")

if __name__ == '__main__':
    main()