python解析Yahoo的XML格式的天气预报，获取当天和近期几天的天气：

下面是接口xml格式数据：

<rss xmlns:yweather="http://xml.weather.yahoo.com/ns/rss/1.0" xmlns:geo="http://www.w3.org/2003/01/geo/wgs84_pos#" version="2.0">

<channel>

<title>Yahoo! Weather - Beijing, CN</title>

<link>

http://us.rd.yahoo.com/dailynews/rss/weather/Beijing__CN/*http://weather.yahoo.com/forecast/CHXX0008_c.html

</link>

<description>Yahoo! Weather for Beijing, CN</description>

<language>en-us</language>

<lastBuildDate>Mon, 06 Oct 2014 5:00 pm CST</lastBuildDate>

<ttl>60</ttl>

<yweather:location city="Beijing" region="" country="China"/>

<yweather:units temperature="C" distance="km" pressure="mb" speed="km/h"/>

<yweather:wind chill="20" direction="200" speed="6.44"/>

<yweather:atmosphere humidity="34" visibility="" pressure="1020.9" rising="0"/>

<yweather:astronomy sunrise="6:14 am" sunset="5:49 pm"/>

<image>

<title>Yahoo! Weather</title>

<width>142</width>

<height>18</height>

<link>http://weather.yahoo.com</link>

<url>

http://l.yimg.com/a/i/brand/purplelogo//uh/us/news-wea.gif

</url>

</image>

<item>

<title>Conditions for Beijing, CN at 5:00 pm CST</title>

<geo:lat>39.91</geo:lat>

<geo:long>116.39</geo:long>

<link>

http://us.rd.yahoo.com/dailynews/rss/weather/Beijing__CN/*http://weather.yahoo.com/forecast/CHXX0008_c.html

</link>

<pubDate>Mon, 06 Oct 2014 5:00 pm CST</pubDate>

<yweather:condition text="Sunny" code="32" temp="20" date="Mon, 06 Oct 2014 5:00 pm CST"/>

<description>

<![CDATA[

<img src="http://l.yimg.com/a/i/us/we/52/32.gif"/><br /> <b>Current Conditions:</b><br /> Sunny, 20 C<BR /> <BR /><b>Forecast:</b><BR /> Mon - Clear. High: 19 Low: 9<br /> Tue - Sunny. High: 22 Low: 10<br /> Wed - Sunny. High: 24 Low: 12<br /> Thu - Sunny. High: 25 Low: 13<br /> Fri - Partly Cloudy. High: 24 Low: 13<br /> <br /> <a href="http://us.rd.yahoo.com/dailynews/rss/weather/Beijing__CN/*http://weather.yahoo.com/forecast/CHXX0008_c.html">Full Forecast at Yahoo! Weather</a><BR/><BR/> (provided by <a href="http://www.weather.com" >The Weather Channel</a>)<br/>

]]>

</description>

<yweather:forecast day="Mon" date="6 Oct 2014" low="9" high="19" text="Clear" code="31"/>

<yweather:forecast day="Tue" date="7 Oct 2014" low="10" high="22" text="Sunny" code="32"/>

<yweather:forecast day="Wed" date="8 Oct 2014" low="12" high="24" text="Sunny" code="32"/>

<yweather:forecast day="Thu" date="9 Oct 2014" low="13" high="25" text="Sunny" code="32"/>

<yweather:forecast day="Fri" date="10 Oct 2014" low="13" high="24" text="Partly Cloudy" code="30"/>

<guid isPermaLink="false">CHXX0008_2014_10_10_7_00_CST</guid>

</item>

</channel>

</rss>

<!--

fan1587.sports.bf1.yahoo.com Mon Oct  6 03:36:02 PDT 2014

-->

Yahoo的XML格式的天气预报，获取当天和近期几天的天气：開始解析：

#-*-coding:UTF-8-*-

import xml.etree.ElementTree as etree

weatherxml = etree.parse('yahooweather.xml')

tree = weatherxml.getroot()

for root in tree:

  #  print root  #channel 直接的一级子元素

    pindao =  tree.findall('channel')

    des = pindao[0].find('title')

    print des.text

    for elem in tree.iter(tag='pubDate'):    #iter() 深度优先搜素遍历

       print elem.text

    for elem in tree.iter(tag='{http://xml.weather.yahoo.com/ns/rss/1.0}condition'):

print elem.attrib

    for elem in tree.iter(tag='{http://xml.weather.yahoo.com/ns/rss/1.0}forecast'):

print elem.attrib

yweather:conditionyweather:forecast冒号前表示命名空间 通过xml文件能够知道yweather=http://xml.weather.yahoo.com/ns/rss/1.0结果：