Refactored code, add new tests and avoid getting value from empty sca…

…lar passing a unit

src/barril/units/_quantity.py

@@ -584,6 +584,9 @@ def GetUnit(self):
 
  unit = property(GetUnit)
 
+ def IsEmpty(self):
+ return self == self._EMPTY_QUANTITY
+
  def GetUnitName(self):
  """
  :rtype: str
@@ -684,10 +687,7 @@ def Convert(self, value, to_unit):
  )
  except ComposedUnitError:
  return self._unit_database.Convert(
- self._category,
- self._CreateUnitsWithJoinedExponentsString(),
- to_unit,
- value,
+ self._category, self._unit, to_unit, value
  )
 
  @classmethod

src/barril/units/_scalar.py

@@ -10,7 +10,7 @@
 from ._abstractvaluewithquantity import AbstractValueWithQuantityObject
 from ._quantity import ObtainQuantity, Quantity
 from .interfaces import IQuantity, IScalar
-from .unit_database import InvalidQuantityTypeError, UnitDatabase
+from .unit_database import InvalidQuantityTypeError, UnitDatabase, UnitsError
 
 __all__ = ["Scalar"]
 
@@ -109,6 +109,10 @@ def GetAbstractValue(self, unit=None):
  if unit is None:
  return self._value
  else:
+ if self._quantity.IsEmpty():
+ raise UnitsError(
+ "Unable to get value for empty quantity, unit should be None."
+ )
  return self._quantity.ConvertScalarValue(self._value, unit)
 
  GetValue = GetAbstractValue
@@ -238,34 +242,35 @@ def GetFormatted(self, unit=None, value_format=None):
  )
 
  # Compare --------------------------------------------------------------------------------------
- def _GetValueInDefaultUnit(self):
+ def _GetValueInBaseUnit(self):
  try:
+ if self._quantity.IsEmpty():
+ return self._value
  return self.GetValue(
- self._unit_database.GetDefaultUnit(self._quantity._category)
+ self._unit_database.GetBaseUnit(self._quantity._category)
  )
  except InvalidQuantityTypeError:
- return self._value
+ return (self._value, self._quantity._unit)
 
  def __eq__(self, other):
  return (
  type(self) is type(other)
  and self._quantity._category == other._quantity._category
- and self._GetValueInDefaultUnit() == other._GetValueInDefaultUnit()
+ and self._GetValueInBaseUnit() == other._GetValueInBaseUnit()
  )
 
  def AlmostEqual(self, other, precision):
  return (
  type(self) is type(other)
  and self._quantity._category == other._quantity._category
  and round(
- self._GetValueInDefaultUnit() - other._GetValueInDefaultUnit(),
- precision,
+ self._GetValueInBaseUnit() - other._GetValueInBaseUnit(), precision
  )
  == 0
  )
 
  def __hash__(self, *args, **kwargs):
- return hash((self._quantity._category, self._GetValueInDefaultUnit()))
+ return hash((self._quantity._category, self._GetValueInBaseUnit()))
 
  def __lt__(self, other):
  if self.quantity_type != other.quantity_type:

src/barril/units/_tests/test_empty_scalar.py

@@ -1,5 +1,5 @@
 from barril.units import Scalar
-from barril.units.unit_database import InvalidQuantityTypeError
+from barril.units.unit_database import InvalidQuantityTypeError, UnitsError
 import pytest
 
 
@@ -18,10 +18,14 @@ def testEmptyScalar():
 def testEmptyScalarWithInitialValue():
  # An empty scalar doesn't have a category defined
  scalar_1 = Scalar.CreateEmptyScalar(20.0)
+ scalar_2 = Scalar.CreateEmptyScalar(20.0)
 
+ assert scalar_1 == scalar_2
  # When try to retrieve an empty scalar value using any unit a exception
  # is being raised
- with pytest.raises(InvalidQuantityTypeError):
+ with pytest.raises(
+ UnitsError, match="Unable to get value for empty quantity, unit should be None."
+ ):
  _ = scalar_1.GetValue("m")
 
  assert scalar_1.GetUnit() == ""

src/barril/units/_tests/test_posc.py

@@ -304,7 +304,6 @@ def testDefaultCategories(unit_database_posc):
  "self inductance per length",
  "shear rate",
  "status",
- "thermodynamic temperature",
  "volume per area",
  "volume per length",
  "volume per time per area",

src/barril/units/_tests/test_posc_additional_units.py

@@ -389,3 +389,17 @@ def testPerMicrometre(db):
  assert approx(per_inch.GetValue()) == 25400
  assert per_metre == units.Scalar("per length", 10 ** 6, "1/m")
  assert per_inch == units.Scalar("per length", 25400.0, "1/in")
+
+
+def testMassTemperaturePerMol(db):
+ value = units.Scalar("mass temperature per mol", 3.1415, "kg.K/mol")
+
+ assert value.GetValue("kg.K/mol") == approx(3.1415)
+ assert value.GetValue("kg.degC/mol") == approx(3.1415)
+ assert value.GetValue("g.K/mol") == approx(3.1415 * 1e3)
+ assert value.GetValue("g.degC/mol") == approx(3.1415 * 1e3)
+ assert value.GetValue("kg.K/kmol") == approx(3.1415 * 1e3)
+ assert value.GetValue("kg.degC/kmol") == approx(3.1415 * 1e3)
+ assert value.GetValue("kg.degF/mol") == approx(3.1415 * 9 / 5)
+ assert value.GetValue("g.degF/mol") == approx(3.1415 * 9 / 5 * 1e3)
+ assert value.GetValue("kg.degF/kmol") == approx(3.1415 * 9 * 1e3 / 5)

src/barril/units/_tests/test_quantity.py

@@ -112,3 +112,10 @@ def testDivision():
  assert speed.GetUnit() == "m/s"
  assert speed.unit == "m/s"
  assert no_unit.GetUnit() == ""
+
+
+def testEmptyQuantity():
+ quantity = Quantity.CreateEmpty()
+ assert quantity.IsEmpty()
+ assert quantity.GetUnit() == ""
+ assert quantity.GetQuantityType() == ""

src/barril/units/_tests/test_scalar.py

@@ -585,7 +585,10 @@ def testScalarCreationModes():
  assert Scalar("length", 10, "m") == base
  assert Scalar((10.0, "m")) == base
 
- with pytest.raises(AssertionError):
+ with pytest.raises(
+ AssertionError,
+ match="If category and value are given, the unit must be specified too.",
+ ):
  Scalar("length", 1.0) # missing unit
 
 
@@ -633,6 +636,8 @@ class Fluid:
 
 
 def testComparison():
+ from math import pi
+
  a = Scalar(1, "m")
  b = Scalar(100, "cm")
  c = Scalar(99, "cm")
@@ -659,3 +664,17 @@ def testComparison():
  a = Scalar(q, 1.0)
  b = Scalar(q * q, 1.0)
  assert {a, b, b / a} == {b, a}
+
+ for value in [0.0, pi, 0.33333333]:
+ a = Scalar("temperature", value, "degC")
+ b = Scalar("temperature", value * 1.8 + 32, "degF")
+ c = Scalar("temperature", value + 273.15, "K")
+
+ assert a <= b <= c and c <= b <= a
+
+
+def testHashing():
+ m = Scalar(1, "m")
+ cm = Scalar(100, "cm")
+ assert m == cm
+ assert hash(m) == hash(cm)

src/barril/units/posc.py

@@ -2665,7 +2665,7 @@ def FillUnitDatabaseWithPosc(db=None, fill_categories=True, override_categories=
  "degF",
  f_base_to_unit,
  f_unit_to_base,
- default_category="thermodynamic temperature",
+ default_category=None,
  )
  f_unit_to_base = MakeCustomaryToBase(0.0, 0.1761102, 1.0, 0.0)
  f_base_to_unit = MakeBaseToCustomary(0.0, 0.1761102, 1.0, 0.0)
@@ -2755,7 +2755,7 @@ def FillUnitDatabaseWithPosc(db=None, fill_categories=True, override_categories=
  "degR",
  f_base_to_unit,
  f_unit_to_base,
- default_category="thermodynamic temperature",
+ default_category=None,
  )
  f_unit_to_base = MakeCustomaryToBase(0.0, 0.1, 1.0, 0.0)
  f_base_to_unit = MakeBaseToCustomary(0.0, 0.1, 1.0, 0.0)