test_eval.py 文件源码

def get_expected_pow_result(self, lhs, rhs):
        try:
            expected = _eval_single_bin(lhs, '**', rhs, self.engine)
        except ValueError as e:
            msg = 'negative number cannot be raised to a fractional power'
            try:
                emsg = e.message
            except AttributeError:
                emsg = e

            emsg = u(emsg)

            if emsg == msg:
                if self.engine == 'python':
                    raise nose.SkipTest(emsg)
                else:
                    expected = np.nan
            else:
                raise
        return expected