python爬虫(12)获取七天内的天气

通过python脚本，来获取最近的天气情况

这样就不必每次打开网站查询天气了

思路分析：

1.决定好要抓取哪个城市的天气情况，获取天气预报网站的页面内容

2.匹配网页内容中天气情况

#!/usr/bin/env python
# coding:utf-8

 
import urllib2,re
from bs4 import BeautifulSoup
import sys
reload(sys)
sys.setdefaultencoding('utf-8')
#导入使用方法模块

 
#这是北京市天气地址，可以换成别的市区
url="http://www.weather.com.cn/weather/101010100.shtml"
def getHtml(url):
	try:
		print url
		html = urllib2.urlopen(url).read()#.decode('utf-8')#解码为utf-8
	except:
		return
	return html
def getWeatherReport(html):
	if not html:
		print 'nothing can be found'
		return
	soup=BeautifulSoup(html,'lxml')
	try:
		items=soup.find("ul",{"class":"t clearfix"})
		result = re.sub(re.compile('\n+'),"\n",str(items.text))
		print result
	except:
		print "something was wrong"
		return
	return result
html=getHtml(url)
getWeatherReport(html)