def test_value_initializes_correctly(self):
with self.assertRaises(TypeError):
_ = Value() # It's a failure test. pylint: disable=no-value-for-parameter
with self.assertRaises(ValueError):
_ = Value(13, 'mugglemeters')
with self.assertRaises(ValueError):
_ = Value(None, 'mugglemeters')
with self.assertRaises(ValueError):
_ = Value(None, 'mm')
x = Value(13, 'mm')
self.assertIsInstance(x, Value)
self.assertFalse(isinstance(x, float))
self.assertTrue(hasattr(x, 'units'))
self.assertEqual(x.units, 'mm')
def test_multiplication(self):
x = Value(25, 'cm')
self.assertEqual(x * 2, 50)
self.assertIsInstance(x * 2, Value)
self.assertEqual(2 * x, 50)
self.assertIsInstance(2 * x, Value)
with self.assertRaises(ValueError):
# This would be cm^2; for our present purposes, multpying Value*Value is an error
_ = x * x
self.assertEqual([1, 2, 3] * x,
[Value(25, 'cm'),
Value(50, 'cm'),
Value(75, 'cm')])
for y in [1, 2, 3] * x:
self.assertIsInstance(y, Value)
def test_easy_conversion_properties(self):
x = Value(25, 'cm')
self.assertAlmostEqual(x.m, 0.25)
self.assertAlmostEqual(x.cm, 25)
self.assertAlmostEqual(x.mm, 250)
with self.assertRaises(AttributeError):
_ = x.mugglemeters
def test_basic_serialization(self):
x = Value(25, 'cm')
x_json = json.dumps(x)
self.assertEquals(x_json,
'{"__value__": {"units": "cm", "value": 25.0}}')
x_obj = json.loads(x_json)
self.assertEquals(x, x_obj)
def test_conversions(self):
x = Value(25, 'cm')
self.assertAlmostEqual(x.convert('m'), 0.25)
self.assertAlmostEqual(x.convert('cm'), 25)
self.assertAlmostEqual(x.convert('mm'), 250)
self.assertAlmostEqual(x.convert('in'), 9.8425197) # from google
self.assertAlmostEqual(x.convert('ft'), 0.82021) # from google
self.assertAlmostEqual(x.convert('fathoms'),
0.136701662) # from google
self.assertAlmostEqual(x.convert('cubits'), 0.546806649) # from google
x = Value(1, 'kg')
self.assertAlmostEqual(x.convert('kg'), 1)
self.assertAlmostEqual(x.convert('g'), 1000)
self.assertAlmostEqual(x.convert('lbs'), 2.20462) # from google
self.assertAlmostEqual(x.convert('stone'), 0.157473) # from google
x = Value(90, 'deg')
self.assertAlmostEqual(x.convert('rad'), np.pi / 2)
self.assertAlmostEqual(x.convert('deg'), 90)
x = Value(30, 'min')
self.assertAlmostEqual(x.convert('sec'), 30 * 60)
self.assertAlmostEqual(x.convert('minutes'), 30)
self.assertAlmostEqual(x.convert('hours'), 0.5)
x = Value(2, 'days')
self.assertAlmostEqual(x.convert('min'), 2 * 24 * 60)
x = Value(1, 'year')
self.assertAlmostEqual(x.convert('min'), 525948.48)
def test_basic_serialization(self):
import six
x = Value(25, 'cm')
x_json = json.dumps(x)
if six.PY2:
self.assertEqual(x_json,
'{"__value__": {"units": "cm", "value": 25.0}}')
else:
self.assertEqual(x_json,
'{"__value__": {"value": 25.0, "units": "cm"}}')
x_obj = json.loads(x_json)
self.assertEqual(x, x_obj)
def input_value(label, units, allow_empty=False):
'''
Read a value from the console, and return an instance of `Value`. The
units are specified by the caller, but displayed to the user.
label: A label for the value (included in the prompt)
units: The units (included in the prompt)
allow_empty: When `True`, allows an empty input. The default is to repeat
until a valid float is entered.
'''
from blmath.value import Value
value = input_float(
prompt='{} ({}): '.format(label, units),
allow_empty=allow_empty
)
if value is None:
return None
return Value(value, units)
def test_value_initializes_with_unitless_values(self):
_ = Value(1, None)
def test_addition_and_subtraction(self):
x = Value(25, 'cm')
self.assertEqual(x + 2, Value(27, 'cm'))
self.assertIsInstance(x + 2, Value)
self.assertEqual(2 + x, Value(27, 'cm'))
self.assertIsInstance(2 + x, Value)
self.assertEqual(x - 2, Value(23, 'cm'))
self.assertIsInstance(x - 2, Value)
# Note that although this is sort of poorly defined, we need to support this case in order to make comparisons easy
self.assertEqual(2 - x, Value(-23, 'cm'))
self.assertIsInstance(2 - x, Value)
self.assertEqual(x + Value(25, 'cm'), Value(50, 'cm'))
self.assertIsInstance(x + Value(25, 'cm'), Value)
self.assertEqual(x + Value(5, 'mm'), Value(255, 'mm'))
self.assertEqual([1, 2, 3] + x,
[Value(26, 'cm'),
Value(27, 'cm'),
Value(28, 'cm')])
for y in [1, 2, 3] + x:
self.assertIsInstance(y, Value)
def test_comparison(self):
self.assertTrue(Value(25, 'cm') == Value(25, 'cm'))
self.assertTrue(Value(25, 'cm') == Value(250, 'mm'))
self.assertTrue(Value(25, 'cm') > Value(240, 'mm'))
self.assertTrue(Value(25, 'cm') < Value(260, 'mm'))
self.assertTrue(Value(25, 'cm') != Value(260, 'mm'))
# When comparison is to a number, we assume that the units are the same as ours
self.assertTrue(Value(25, 'cm') == 25)
def test_behaves_like_tuple(self):
x = Value(25, 'cm')
self.assertAlmostEqual(x[0], 25)
self.assertAlmostEqual(x[1], 'cm')
def test_other_numeric_methods(self):
x = Value(25, 'cm')
self.assertEqual(str(x), "25.000000 cm")
self.assertEqual(x / 2.0, Value(12.5, 'cm'))
self.assertIsInstance(x / 2.0, Value)
self.assertEqual(x / Value(1, 'cm'), Value(25, None))
self.assertEqual(x / Value(1, 'm'), Value(0.25, None))
self.assertEqual(x // 2, Value(12, 'cm'))
self.assertEqual(x // Value(1, 'cm'), Value(25, None))
self.assertEqual(x // Value(1, 'm'), Value(0, None))
self.assertIsInstance(x // 2, Value)
with self.assertRaises(AttributeError):
_ = x % 2
with self.assertRaises(AttributeError):
_ = x**2
with self.assertRaises(ValueError):
_ = 2.0 / x
self.assertEqual(+x, Value(25, 'cm'))
self.assertIsInstance(+x, Value)
self.assertEqual(-x, Value(-25, 'cm'))
self.assertIsInstance(-x, Value)
self.assertEqual(abs(Value(-25, 'cm')), Value(25, 'cm'))
self.assertIsInstance(abs(Value(-25, 'cm')), Value)
def test_value_does_not_convert_unitless_values(self):
x = Value(1, None)
with self.assertRaises(ValueError):
x.convert('kg')
def test_cast(self):
x = Value(25, 'cm')
self.assertEqual(float(x), x.value)
self.assertEqual(int(x), x.value)
self.assertEqual(int(Value(25.5, 'cm')), 25)
def test_exception_raised_if_value_is_nonsense(self):
with self.assertRaises(ValueError):
Value('x', 'mm')
v = Value(0, 'mm')
with self.assertRaises(ValueError):
v.value = 'x'
def test_make_numpy_array_out_of_values(self):
x = np.array([Value(i, 'cm') for i in range(10)])
res = np.sum(x)
self.assertIsInstance(res, Value)
def test_complex_serialization(self):
x = {str(i): Value(i, 'cm') for i in range(10)}
x_json = json.dumps(x)
x_obj = json.loads(x_json)
self.assertEqual(x, x_obj)