core/homeassistant/util/unit_system.py

125 lines
3.8 KiB
Python

"""Unit system helper class and methods."""
import logging
from numbers import Number
from homeassistant.const import (
TEMP_CELSIUS, TEMP_FAHRENHEIT, LENGTH_CENTIMETERS, LENGTH_METERS,
LENGTH_KILOMETERS, LENGTH_INCHES, LENGTH_FEET, LENGTH_YARD, LENGTH_MILES,
VOLUME_LITERS, VOLUME_MILLILITERS, VOLUME_GALLONS, VOLUME_FLUID_OUNCE,
MASS_GRAMS, MASS_KILOGRAMS, MASS_OUNCES, MASS_POUNDS,
CONF_UNIT_SYSTEM_METRIC, CONF_UNIT_SYSTEM_IMPERIAL, LENGTH, MASS, VOLUME,
TEMPERATURE, UNIT_NOT_RECOGNIZED_TEMPLATE)
from homeassistant.util import temperature as temperature_util
from homeassistant.util import distance as distance_util
_LOGGER = logging.getLogger(__name__)
LENGTH_UNITS = [
LENGTH_MILES,
LENGTH_YARD,
LENGTH_FEET,
LENGTH_INCHES,
LENGTH_KILOMETERS,
LENGTH_METERS,
LENGTH_CENTIMETERS,
]
MASS_UNITS = [
MASS_POUNDS,
MASS_OUNCES,
MASS_KILOGRAMS,
MASS_GRAMS,
]
VOLUME_UNITS = [
VOLUME_GALLONS,
VOLUME_FLUID_OUNCE,
VOLUME_LITERS,
VOLUME_MILLILITERS,
]
TEMPERATURE_UNITS = [
TEMP_FAHRENHEIT,
TEMP_CELSIUS,
]
def is_valid_unit(unit: str, unit_type: str) -> bool:
"""Check if the unit is valid for it's type."""
if unit_type == LENGTH:
units = LENGTH_UNITS
elif unit_type == TEMPERATURE:
units = TEMPERATURE_UNITS
elif unit_type == MASS:
units = MASS_UNITS
elif unit_type == VOLUME:
units = VOLUME_UNITS
else:
return False
return unit in units
class UnitSystem(object):
"""A container for units of measure."""
def __init__(self: object, name: str, temperature: str, length: str,
volume: str, mass: str) -> None:
"""Initialize the unit system object."""
errors = \
', '.join(UNIT_NOT_RECOGNIZED_TEMPLATE.format(unit, unit_type)
for unit, unit_type in [
(temperature, TEMPERATURE),
(length, LENGTH),
(volume, VOLUME),
(mass, MASS), ]
if not is_valid_unit(unit, unit_type)) # type: str
if errors:
raise ValueError(errors)
self.name = name
self.temperature_unit = temperature
self.length_unit = length
self.mass_unit = mass
self.volume_unit = volume
@property
def is_metric(self: object) -> bool:
"""Determine if this is the metric unit system."""
return self.name == CONF_UNIT_SYSTEM_METRIC
def temperature(self: object, temperature: float, from_unit: str) -> float:
"""Convert the given temperature to this unit system."""
if not isinstance(temperature, Number):
raise TypeError(
'{} is not a numeric value.'.format(str(temperature)))
return temperature_util.convert(temperature,
from_unit, self.temperature_unit)
def length(self: object, length: float, from_unit: str) -> float:
"""Convert the given length to this unit system."""
if not isinstance(length, Number):
raise TypeError('{} is not a numeric value.'.format(str(length)))
return distance_util.convert(length, from_unit,
self.length_unit)
def as_dict(self) -> dict:
"""Convert the unit system to a dictionary."""
return {
LENGTH: self.length_unit,
MASS: self.mass_unit,
TEMPERATURE: self.temperature_unit,
VOLUME: self.volume_unit
}
METRIC_SYSTEM = UnitSystem(CONF_UNIT_SYSTEM_METRIC, TEMP_CELSIUS,
LENGTH_KILOMETERS, VOLUME_LITERS, MASS_GRAMS)
IMPERIAL_SYSTEM = UnitSystem(CONF_UNIT_SYSTEM_IMPERIAL, TEMP_FAHRENHEIT,
LENGTH_MILES, VOLUME_GALLONS, MASS_POUNDS)