'æåè¥¿åºä»£ç http://api.xicidaili.com/free2016.txt
:return:'

@staticmethod
@robustCrawl
def freeProxyFourth():

    url_list = ['http://www.xicidaili.com/nn', 'http://www.xicidaili.com/nt']
    for each_url in url_list:
        tree = getHtmlTree(each_url)
        proxy_list = tree.xpath('.//table[@id="ip_list"]//tr')
        for proxy in proxy_list:
            (yield ':'.join(proxy.xpath('./td/text()')[0:2]))
