Units Reference

openhtf.util.units defines one UnitDescriptor constant per unit of measure, generated from the UNECE Recommendation 20 code list. Attach one to a measurement with .with_units(); it is stored in the record as {name, code, suffix} so downstream tools can label and convert values.

import openhtf as htf
from openhtf.util import units

@htf.measures(
    htf.Measurement("supply_voltage").in_range(3.2, 3.4).with_units(units.VOLT),
    htf.Measurement("board_temp").in_range(0, 60).with_units(units.DEGREE_CELSIUS),
    htf.Measurement("boot_time").in_range(maximum=2.5).with_units(units.SECOND),
    htf.Measurement("rssi").in_range(-70, 0).with_units(units.DECIBEL_MILLIWATTS),
)
def measure(test):
    ...

Look up by string

units.Unit() resolves a unit from its name, suffix or code, and .with_units() accepts a string directly:

units.Unit('V')               # -> units.VOLT
units.Unit('metre per second')  # -> units.METRE_PER_SECOND
htf.Measurement('r').with_units('ohm')   # string form, same result

Two special constants: units.NONE (no unit) and units.NO_DIMENSION (a ratio or count that has a unit conceptually but no dimension).

Common units

Spellings follow the UNECE names, which are not always what you would guess (KILOOHM, MEGAOHM, DECIBEL_MILLIWATTS, MICROMETRE_MICRON, BAR_UNIT_OF_PRESSURE); use the filter below to confirm before you type.

All units