core/homeassistant/util/temperature.py

35 lines
1.2 KiB
Python

"""Temperature util functions."""
from homeassistant.const import (
TEMP_CELSIUS,
TEMP_FAHRENHEIT,
UNIT_NOT_RECOGNIZED_TEMPLATE,
TEMPERATURE
)
def fahrenheit_to_celsius(fahrenheit: float) -> float:
"""Convert a Fahrenheit temperature to Celsius."""
return (fahrenheit - 32.0) / 1.8
def celsius_to_fahrenheit(celsius: float) -> float:
"""Convert a Celsius temperature to Fahrenheit."""
return celsius * 1.8 + 32.0
def convert(temperature: float, from_unit: str, to_unit: str) -> float:
"""Convert a temperature from one unit to another."""
if from_unit not in (TEMP_CELSIUS, TEMP_FAHRENHEIT):
raise ValueError(UNIT_NOT_RECOGNIZED_TEMPLATE.format(from_unit,
TEMPERATURE))
if to_unit not in (TEMP_CELSIUS, TEMP_FAHRENHEIT):
raise ValueError(UNIT_NOT_RECOGNIZED_TEMPLATE.format(to_unit,
TEMPERATURE))
if from_unit == to_unit:
return temperature
elif from_unit == TEMP_CELSIUS:
return celsius_to_fahrenheit(temperature)
else:
return fahrenheit_to_celsius(temperature)