#!/usr/bin/env python3
# Copyright © 2014 Mattias Andrée (maandree@member.fsf.org)
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
from subprocess import Popen, PIPE
def weather(station):
'''
Get a brief weather report
@param station:str The station's International Civil Aviation Organization airport code
@return :(sky:str, visiblity:(:int, :float)?, weather:list<str>)
The sky condition, visiblity and weather. Sky condition values include
‘clear’, ‘mostly clear’, ‘overcast’, ‘partly cloudy’, ‘mostly cloudy’
and ‘obscured’. The visibility consists of two parameters: the first
on indicates the the visiblity is a upper bound if the value is -1,
a lower bound if +1, and approximate if 0; the second parameter is the
visibility in kilometers. If the visibility is unknown the value will
be `None`. The weather is a list that can, and often is, empty.
'''
url = 'http://weather.noaa.gov/pub/data/observations/metar/decoded/%s.TXT'
url %= station.upper()
proc = Popen(['wget', url, '-O', '-'], stdout = PIPE, stderr = PIPE)
output = proc.communicate()[0]
if not proc.returncode == 0:
return None
output = output.decode('utf-8', 'replace').split('\n')
output = [line.lower().split(': ') for line in output if ': ' in line]
output = dict([(line[0], ': '.join(line[1:])) for line in output])
sky_conditions = 'clear' if 'sky conditions' not in output else output['sky conditions']
visibility = None
try:
if 'visibility' in output:
visibility = output['visibility'].split(':')[0]
visibility = visibility.replace(' mile(s)', '')
visibility = visibility.replace(' miles', '')
visibility = visibility.replace(' mile', '')
visibility_eq = 0
if visibility.startswith('greater than '):
visibility_eq = 1
visibility = visibility[len('greater than '):]
if visibility.startswith('less than '):
visibility_eq = -1
visibility = visibility[len('less than '):]
if len(list(filter(lambda c : not (('0' <= c <= '9') or (c in ' /')), visibility))) == 0:
visibility = sum([eval(v) for v in visibility.split(' ')])
visibility = (visibility_eq, visibility * 1.609)
else:
visibility = None
except:
visibility = None
weather = '' if 'weather' not in output else output['weather']
weather = weather.replace(',', ';').replace(' with ', ';')
weather = weather.replace(' in the vicinity', '')
weather = weather.replace(' observed', '')
weather = weather.replace(' during the past hour', '')
weather = [w.replace(';', '').strip() for w in weather.split(';') if not w == '']
return (sky_conditions, visibility, weather)
