add owm.py: get weather data from openweathermap

this script can replace wetter.at.pl:

perl:   2018-06-08;19:00;   05:21   ;21:09   ;21   ;0 mm/h;7km/h O     ;stark bewölkt      ;93
python: 2018-06-08;20:20:00;05:20:24;21:10:53;17.13;      ;2.6km/h O   ;Überwiegend bewölkt;75

and can be extended to write to the mysql database and a csv file like
seewasser.py

(and probably parts of seewasser.py could be extracted as common functions)

owm.py needs an api key from openweathermap and some config; cf. the
comments ath the top

questions:
- is precipitation really missing from json and available in xml?
- the str() casting at the end looks ugly

diff --git a/owm.py b/owm.py
new file mode 100755 (executable)
index 0000000..04d38b5
--- /dev/null
+++ b/owm.py
@@ -0,0 +1,100 @@
+#!/usr/bin/python3
+
+# needs ~/seepark.ini with
+# [openweathermap]
+# apikey=...
+# cityid=..
+# 3319578 for Obsteig, AT
+
+from pprint import pprint
+import requests
+import configparser
+import os
+import datetime
+
+baseurl = 'http://api.openweathermap.org/data/2.5/weather'
+debug = False
+
+def getweather(apikey, cityid):
+    query = baseurl + '?units=metric&APPID={}&id={}&lang=de'.format(apikey, cityid)
+    try:
+        response = requests.get(query)
+        if response.status_code != 200:
+            response = 'N/A'
+            return response
+        else:
+            weatherdata = response.json()
+            return weatherdata
+    except requests.exceptions.RequestException as error:
+        print (error)
+        sys.exit(1)
+
+
+def fromtimestamp(timestamp, format):
+    return datetime.datetime.fromtimestamp(timestamp).strftime(format)
+
+
+# https://stackoverflow.com/questions/7490660/converting-wind-direction-in-angles-to-text-words
+def degToCompass(num):
+    val=int((num/22.5)+.5)
+    arr=["N","NNO","NO","ONO","O","OSO", "SO", "SSO","S","SSW","SW","WSW","W","WNW","NW","NNW"]
+    return arr[(val % 16)]
+
+
+def extractweatherdata(w):
+    data = dict(
+        datetime = w.get('dt'),
+        sunrise = w.get('sys').get('sunrise'),
+        sunset = w.get('sys').get('sunset'),
+        temp = w.get('main').get('temp'),
+        pressure = w.get('main').get('pressure'),
+        humidity = w.get('main').get('humidity'),
+        visibility = w.get('visibility'),
+        weather=w['weather'][0]['description'],
+        sky=w['weather'][0]['main'],
+        windspeed=w.get('wind').get('speed'),
+        winddegrees=w.get('wind').get('deg'),
+        cloudiness=w.get('clouds').get('all'),
+    )
+
+    data['sunrise_t'] = fromtimestamp(data['sunrise'], '%H:%M:%S')
+    data['sunset_t'] = fromtimestamp(data['sunset'], '%H:%M:%S')
+    data['date'] = fromtimestamp(data['datetime'], '%Y-%m-%d')
+    data['time'] = fromtimestamp(data['datetime'], '%H:%M:%S')
+    data['winddirection'] = degToCompass(data['winddegrees'])
+
+    return data
+        
+
+def main():
+    config = configparser.ConfigParser()
+    config.read(os.path.expanduser('~/seewasser.ini'))
+    apikey = config.get('openweathermap', 'apikey');
+    cityid = config.get('openweathermap', 'cityid');
+
+    weather_raw = getweather(apikey, cityid)
+    if debug:
+        pprint(weather_raw)
+    weather = extractweatherdata(weather_raw)
+    if debug:
+        pprint(weather)
+    # TODO:
+    # write to db
+    # write to csv
+    
+    # output like wetter.at.pl
+    print(
+        weather['date'] + ';' +
+        weather['time'] + ';' +
+        weather['sunrise_t'] + ';' +
+        weather['sunset_t'] + ';' +
+        str(weather['temp']) + ';' +
+        ';' + # precipitation missing? or only in XML: https://openweathermap.org/current ?
+        str(weather['windspeed']) + 'km/h ' + weather['winddirection'] + ';' +
+        weather['weather'] + ';' +
+        str(weather['cloudiness'])
+    )
+
+    
+if __name__ == '__main__':
+    main()