def test_multiply(self):
# multiplication should error for units with offsets
x = _find_unit('g')
y = _find_unit('s')
z = _find_unit('degC')
self.assertEqual(
x * y,
PhysicalUnit({
's': 1,
'kg': 1
}, .001, _get_powers(mass=1, time=1), 0))
self.assertEqual(
y * x,
PhysicalUnit({
's': 1,
'kg': 1
}, .001, _get_powers(mass=1, time=1), 0))
try:
x * z
except TypeError as err:
self.assertEqual(str(err),
"cannot multiply units with non-zero offset")
else:
self.fail("Expecting TypeError")
def test_division(self):
# division should error when working with offset units
w = _find_unit('kg')
x = _find_unit('g')
y = _find_unit('s')
z = _find_unit('degC')
quo = w / x
quo2 = x / y
self.assertEqual(quo, PhysicalUnit({'kg': 1, 'g': -1},
1000.0, _get_powers(), 0))
self.assertEqual(quo2, PhysicalUnit({'s': -1, 'g': 1},
0.001,
_get_powers(mass=1, time=-1), 0))
quo = y / 2.0
self.assertEqual(quo, PhysicalUnit({'s': 1, "2.0": -1},
.5, _get_powers(time=1), 0))
quo = 2.0 / y
self.assertEqual(quo, PhysicalUnit({'s': -1, "2.0": 1}, 2,
_get_powers(time=-1), 0))
try:
x / z
except TypeError as err:
self.assertEqual(
str(err), "Can't divide units: either 'g' or 'degC' has a non-zero offset.")
else:
self.fail("Expecting TypeError")