opensemantic.characteristics.quantitative 0.5.1.post1000004001002

Library with Python models derived from the page package world.opensemantic.characteristics.quantitative

opensemantic.characteristics.quantitative

Library with Python models derived from the page package world.opensemantic.characteristics.quantitative

Quantities and units generated from QUDT. pint mapping was done with support from ucumvert

Usage

from opensemantic.characteristics.quantitative import (
    Length, LengthUnit, Width, Area, AreaUnit, QuantityValue,
)

# Create typed quantity values
length = Length(value=1.0, unit=LengthUnit.meter)
width = Width(value=200, unit=LengthUnit.milli_meter)

# Arithmetic — units are tracked automatically via pint
area = length * width
print(area.value, area.unit.name)  # 200000.0 milli_meter_squared
assert isinstance(area, Area)

# Unit conversion
area_cm2 = area.to_unit(AreaUnit.centi_meter_squared)
print(area_cm2.value)  # 2000.0
assert area == area_cm2  # physical equality across units

# Addition with automatic unit conversion
l1 = Length(value=1.0, unit=LengthUnit.milli_meter)
l2 = Length(value=1.0, unit=LengthUnit.meter)
print((l1 + l2).value)  # 1.001 (in meters)

# pint interop: round-trip to/from pint.Quantity
q_pint = l1.to_pint()                    # -> 1.0 millimeter
restored = QuantityValue.from_pint(q_pint)  # -> Length(1.0, milli_meter)
assert l1 == restored

# JSON serialization (via oold's unified API)
print(l1.to_json())
# {'type': ['Category:OSWee9c7e5c...'], 'value': 1.0, 'unit': 'Item:OSWf101d25e...'}

Round-tripping derived units

from_pint recovers a typed QuantityValue even when the exact unit symbol is not in the registry - e.g. derived units (watt, joule, ohm) or composed results such as volt * ampere. When the symbol is unknown it falls back to the quantity's dimensionality, mapping it to a representative SI-coherent unit via DIMENSION_TO_UNIT (generated into _dimensions.py by scripts/post_process.py):

from opensemantic.characteristics.quantitative import (
    Voltage, VoltageUnit, ElectricCurrent, ElectricCurrentUnit, Power,
)

power = Voltage(value=3.7, unit=VoltageUnit.volt) * ElectricCurrent(
    value=2.0, unit=ElectricCurrentUnit.ampere
)
assert isinstance(power, Power)  # volt * ampere -> watt

Compact export

exclude_defaults=True omits values left at their default (e.g. the default unit) for a minimal, portable representation:

length = Length(value=1.0, unit=LengthUnit.meter)
print(length.to_json(exclude_defaults=True))  # {'value': 1.0}

See examples/ for more, including tabular data with pandas and a tensile test analysis.

TODO: Unit Name Conflicts in _collection.py

18 unit member names appear in multiple *Unit enum classes with different OSW IDs. The first occurrence goes into _collection.py; conflicting entries remain hardcoded in _model.py. These likely stem from upstream QUDT modeling where the same unit name maps to different physical quantities.

Name	Classes (conflicting OSW IDs)
day	TimeUnit vs HydraulicPermeabilityUnit
kilo_newton	ForceUnit vs TorquePerLengthUnit
kilo_newton_per_meter	EnergyPerAreaUnit vs ForcePerLengthUnit
liter_per_meter_squared_per_second	VolumetricFluxUnit vs VentilationRatePerFloorAreaUnit
meter	LengthUnit vs AreaPerLengthUnit vs VolumePerUnitAreaUnit
meter_pascal	StressIntensityFactorUnit vs UnknownUnit
milli_newton_per_meter	EnergyPerAreaUnit vs ForcePerLengthUnit
minute	TimeUnit vs PlaneAngleUnit
newton	ForceUnit vs TorquePerLengthUnit
newton_per_meter	EnergyPerAreaUnit vs ForcePerLengthUnit
pH_value	InductanceUnit vs BasicityUnit
per_centi_meter	InverseLengthUnit vs UnknownUnit
per_day	FrequencyUnit vs UnknownUnit vs MassSpecificBiogeochemicalRateUnit
per_hour	FrequencyUnit vs MassSpecificBiogeochemicalRateUnit
per_meter	InverseLengthUnit vs UnknownUnit
per_meter_1	InverseLengthUnit vs UnknownUnit
per_minute	FrequencyUnit vs RotationalFrequencyUnit
year	AreaUnit vs TimeUnit

Status

pint round-trip (full inventory): 0 unit_registry misses

tests/conversion_test.py::test_full_inventory_test round-trips every QuantityValue x unit through to_pint() / from_pint() and now asserts zero unit_registry misses (v2: 2089 ok / 282 errors; v1: 3181 ok / 442 errors). from_pint resolves every unit whose symbol pint can parse - derived units fall back to the dimensionality map in _dimensions.py. The remaining errors are all UndefinedUnitError (units pint itself does not define, e.g. astronomical_unit, electron_volt, metric_ton, sidereal time units); the critical warnings are units shared by several quantities of the same dimensionality (value + unit still round-trip, but the class may resolve to a sibling).

Note

This project has been set up using PyScaffold 4.6. For details and usage information on PyScaffold see https://pyscaffold.org/.