def tail_degrees(f):
        if not f:
            return (-oo,)*f.ring.ngens
        else:
            return tuple(map(min, list(zip(*f.itermonoms()))))
Make sure __str__/__unicode__ works correctly in Python 2/3
dataset/ETHPy150Open sympy/sympy/sympy/polys/rings.py/PolyElement.tail_degrees--crossover with--dataset/ETHPy150Open recurly/recurly-client-python/tests/tests_errors.py/RecurlyExceptionTests.test_validationerror_printable