Mercurial > personal > weather-server
view weather_server/types.py @ 35:2f3473416c11
Fix format string in repr(Location).
author | Paul Fisher <paul@pfish.zone> |
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date | Fri, 02 Jul 2021 20:36:56 -0400 |
parents | beb42c835c52 |
children |
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"""Basic data types for the weather server.""" import datetime import math import typing as t import attr T = t.TypeVar('T') def c_to_f(c: float) -> float: return c * 9 / 5 + 32 # Values from Sontag1990 via Wikipedia: # https://en.wikipedia.org/wiki/Dew_point _MAGNUS_B = 17.62 _MAGNUS_C = 243.12 @attr.s(frozen=True, slots=True) class Reading: """A single reading from a weather thingy. Field order is important, as it is used in CSV files. """ # The Unix timestamp of the reading. sample_time = attr.ib(type=datetime.datetime) # The temperature, in degrees Celsius. temp_c = attr.ib(type=float) # The relative humidity, in percent. rh_pct = attr.ib(type=float) # The Unix timestamp when the reading was received. ingest_time = attr.ib(type=datetime.datetime) @property def temp_f(self) -> float: return c_to_f(self.temp_c) @property def dew_point_c(self) -> float: gamma = self._gamma return _MAGNUS_C * gamma / (_MAGNUS_B - gamma) @property def dew_point_f(self) -> float: return c_to_f(self.dew_point_c) @classmethod def from_dict(cls: t.Type[T], d: t.Dict[str, t.Any]) -> T: return cls(**{f.name: d[f.name] for f in attr.fields(cls)}) @property def _gamma(self) -> float: return ( math.log(self.rh_pct / 100) + _MAGNUS_B * self.temp_c / (_MAGNUS_C + self.temp_c))