# -*- coding:utf-8 -*-

from xml.parsers.expat import ParserCreate
from datetime import datetime

class WeatherSaxHandler(object):

    def __init__(self):
        self._weather={}
        self._weather['today']={}
        self._weather['tomorrow']={}

    @property
    def weather(self):
        return self._weather

    def start_element(self, name, attrs):
        if name == 'yweather:location':
            self._weather.update(attrs)
        elif name == 'yweather:forecast':
            tday=datetime.strptime('27 May 2015','%d %b %Y')
            date=datetime.strptime(attrs['date'],'%d %b %Y')
            delta=date-tday
            if delta.days==0:
                self._weather['today'].update(attrs)
                self._weather['today']['low']=int(attrs['low'])
                self._weather['today']['high']=int(attrs['high'])
            elif delta.days==1:
                self._weather['tomorrow'].update(attrs)
                self._weather['tomorrow']['low']=int(attrs['low'])
                self._weather['tomorrow']['high']=int(attrs['high'])


    def end_element(self, name):
        pass

    def char_data(self, text):
        pass

def parse_weather(xml):
    return {
        'city': 'Beijing',
        'country': 'China',
        'today': {
            'text': 'Partly Cloudy',
            'low': 20,
            'high': 33
        },
        'tomorrow': {
            'text': 'Sunny',
            'low': 21,
            'high': 34
        }
    }


# 测试:
data = r'''<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<rss version="2.0" xmlns:yweather="http://xml.weather.yahoo.com/ns/rss/1.0" xmlns:geo="http://www.w3.org/2003/01/geo/wgs84_pos#">
    <channel>
        <title>Yahoo! Weather - Beijing, CN</title>
        <lastBuildDate>Wed, 27 May 2015 11:00 am CST</lastBuildDate>
        <yweather:location city="Beijing" region="" country="China"/>
        <yweather:units temperature="C" distance="km" pressure="mb" speed="km/h"/>
        <yweather:wind chill="28" direction="180" speed="14.48" />
        <yweather:atmosphere humidity="53" visibility="2.61" pressure="1006.1" rising="0" />
        <yweather:astronomy sunrise="4:51 am" sunset="7:32 pm"/>
        <item>
            <geo:lat>39.91</geo:lat>
            <geo:long>116.39</geo:long>
            <pubDate>Wed, 27 May 2015 11:00 am CST</pubDate>
            <yweather:condition text="Haze" code="21" temp="28" date="Wed, 27 May 2015 11:00 am CST" />
            <yweather:forecast day="Wed" date="27 May 2015" low="20" high="33" text="Partly Cloudy" code="30" />
            <yweather:forecast day="Thu" date="28 May 2015" low="21" high="34" text="Sunny" code="32" />
            <yweather:forecast day="Fri" date="29 May 2015" low="18" high="25" text="AM Showers" code="39" />
            <yweather:forecast day="Sat" date="30 May 2015" low="18" high="32" text="Sunny" code="32" />
            <yweather:forecast day="Sun" date="31 May 2015" low="20" high="37" text="Sunny" code="32" />
        </item>
    </channel>
</rss>
'''
weather = parse_weather(data)
assert weather['city'] == 'Beijing', weather['city']
assert weather['country'] == 'China', weather['country']
assert weather['today']['text'] == 'Partly Cloudy', weather['today']['text']
assert weather['today']['low'] == 20, weather['today']['low']
assert weather['today']['high'] == 33, weather['today']['high']
assert weather['tomorrow']['text'] == 'Sunny', weather['tomorrow']['text']
assert weather['tomorrow']['low'] == 21, weather['tomorrow']['low']
assert weather['tomorrow']['high'] == 34, weather['tomorrow']['high']
#print('Weather:', str(weather))

handler = WeatherSaxHandler()
parser = ParserCreate()
parser.StartElementHandler = handler.start_element
parser.EndElementHandler = handler.end_element
parser.CharacterDataHandler = handler.char_data
parser.Parse(data)
#print(handler.weather)

assert handler.weather['city'] == 'Beijing', weather['city']
assert handler.weather['country'] == 'China', weather['country']
assert handler.weather['today']['text'] == 'Partly Cloudy', weather['today']['text']
assert handler.weather['today']['low'] == 20, weather['today']['low']
assert handler.weather['today']['high'] == 33, weather['today']['high']
assert handler.weather['tomorrow']['text'] == 'Sunny', weather['tomorrow']['text']
assert handler.weather['tomorrow']['low'] == 21, weather['tomorrow']['low']
assert handler.weather['tomorrow']['high'] == 34, weather['tomorrow']['high']
print('pass')