'Ensure division by zero gives an error'

def test_raises_zero_division_err(self):

    with self.assertRaises(ZeroDivisionError):
        calc.evaluator({}, {}, '1/0')
    with self.assertRaises(ZeroDivisionError):
        calc.evaluator({}, {}, '1/0.0')
    with self.assertRaises(ZeroDivisionError):
        calc.evaluator({'x': 0.0}, {}, '1/x')
