天气信息+迭代器

从网址中抓取城市的天气信息，实现可迭代对象和迭代器对象，从而方便的进行一组城市的天气信息查询

# encoding=utf-8
import requests
# *************************************************************************************
# 实现从网站中抓取天气信息
# def getWeather(city):
#     r = requests.get(u'http://wthrcdn.etouch.cn/weather_mini?city=' + city)
#     data = r.json()['data']['forecast'][0]
#     return '%s:%s,%s' % (city,data['low'],data['high'])

 # print getWeather(u'北京')
 # print getWeather(u'沈阳')
# ***************************************************************************************
from collections import Iterable,Iterator

class WeatherIterator(Iterator):
    def __init__(self,cities):
        self.cities = cities
        self.index = 0
    
    def getWeather(self,city):
        r = requests.get(u'http://wthrcdn.etouch.cn/weather_mini?city=' + city)
        data = r.json()['data']['forecast'][0]
        return '%s:%s,%s' % (city,data['low'],data['high'])
    
    def next(self):
        if self.index == len(self.cities):
            raise StopIteration
        city = self.cities[self.index]
        self.index += 1
        return self.getWeather(city)
        
class WeatherIterable(Iterable):
    def __init__(self,cities):
        self.cities = cities
    
    def __iter__(self):
        return WeatherIterator(self.cities)
        
        
        
for x in WeatherIterable([u'北京',u'上海',u'沈阳',u'郑州']):
        print x