cached/weather_forecast.py

   1 #!/usr/bin/env python3
   2
   3 from dataclasses import dataclass
   4 import datetime
   5 import logging
   6 import urllib.request
   7
   8 import astral  # type: ignore
   9 from astral.sun import sun  # type: ignore
  10 from bs4 import BeautifulSoup  # type: ignore
  11 import pytz
  12
  13 import argparse_utils
  14 import config
  15 import datetime_utils
  16 import dateparse.dateparse_utils as dp
  17 import persistent
  18 import text_utils
  19
  20 logger = logging.getLogger(__name__)
  21
  22 cfg = config.add_commandline_args(
  23     f'Cached Weather Forecast ({__file__})',
  24     'Arguments controlling detailed weather rendering'
  25 )
  26 cfg.add_argument(
  27     '--weather_forecast_cachefile',
  28     type=str,
  29     default='/home/scott/.weather_forecast_cache',
  30     metavar='FILENAME',
  31     help='File in which to cache weather data'
  32 )
  33 cfg.add_argument(
  34     '--weather_forecast_stalest_acceptable',
  35     type=argparse_utils.valid_duration,
  36     default=datetime.timedelta(seconds=7200),   # 2 hours
  37     metavar='DURATION',
  38     help='Maximum acceptable age of cached data.  If zero, forces a refetch'
  39 )
  40
  41
  42 @dataclass
  43 class WeatherForecast:
  44     date: datetime.date                # The date
  45     sunrise: datetime.datetime         # Sunrise datetime
  46     sunset: datetime.datetime          # Sunset datetime
  47     description: str                   # Textual description of weather
  48
  49
  50 @persistent.persistent_autoloaded_singleton()
  51 class CachedDetailedWeatherForecast(object):
  52     def __init__(self, forecasts = None):
  53         if forecasts is not None:
  54             self.forecasts = forecasts
  55             return
  56
  57         now = datetime_utils.now_pacific()
  58         self.forecasts = {}
  59
  60         # Ask the raspberry pi about the outside temperature.
  61         www = urllib.request.urlopen(
  62             "http://10.0.0.75/~pi/outside_temp"
  63         )
  64         current_temp = www.read().decode("utf-8")
  65         current_temp = float(current_temp)
  66         current_temp *= (9/5)
  67         current_temp += 32.0
  68         current_temp = round(current_temp)
  69         www.close()
  70
  71         # Get a weather forecast for Bellevue.
  72         www = urllib.request.urlopen(
  73             "https://forecast.weather.gov/MapClick.php?lat=47.652775&lon=-122.170716"
  74         )
  75         forecast_response = www.read()
  76         www.close()
  77
  78         soup = BeautifulSoup(forecast_response, "html.parser")
  79         forecast = soup.find(id='detailed-forecast-body')
  80         parser = dp.DateParser()
  81
  82         last_dt = now
  83         dt = now
  84         for (day, txt) in zip(
  85                 forecast.find_all('b'),
  86                 forecast.find_all(class_='col-sm-10 forecast-text')
  87         ):
  88             last_dt = dt
  89             try:
  90                 dt = parser.parse(day.get_text())
  91             except Exception:
  92                 dt = last_dt
  93             assert dt is not None
  94
  95             # Compute sunrise/sunset times on dt.
  96             city = astral.LocationInfo(
  97                 "Bellevue", "USA", "US/Pacific", 47.653, -122.171
  98             )
  99             s = sun(city.observer, date=dt, tzinfo=pytz.timezone("US/Pacific"))
 100             sunrise = s['sunrise']
 101             sunset = s['sunset']
 102
 103             if dt.date == now.date:
 104                 blurb = f'{day.get_text()}: The current outside tempterature is {current_temp}.  ' + txt.get_text()
 105             else:
 106                 blurb = f'{day.get_text()}: {txt.get_text()}'
 107             blurb = text_utils.wrap_string(blurb, 80)
 108
 109             if dt.date() in self.forecasts:
 110                 self.forecasts[dt.date()].description += '\n' + blurb
 111             else:
 112                 self.forecasts[dt.date()] = WeatherForecast(
 113                     date = dt,
 114                     sunrise = sunrise,
 115                     sunset = sunset,
 116                     description = blurb,
 117                 )
 118
 119     @classmethod
 120     def load(cls):
 121         if persistent.was_file_written_within_n_seconds(
 122                 config.config['weather_forecast_cachefile'],
 123                 config.config['weather_forecast_stalest_acceptable'].total_seconds(),
 124         ):
 125             import pickle
 126             with open(config.config['weather_forecast_cachefile'], 'rb') as rf:
 127                 weather_data = pickle.load(rf)
 128                 return cls(weather_data)
 129         return None
 130
 131     def save(self):
 132         import pickle
 133         with open(config.config['weather_forecast_cachefile'], 'wb') as wf:
 134             pickle.dump(
 135                 self.forecasts,
 136                 wf,
 137                 pickle.HIGHEST_PROTOCOL,
 138             )