嵌套抓取子元素
soup = BeautifulSoup(html_doc,'html.parser', from_encoding='utf-8')
tableArea=soup.find('table',class="table table-hover table-striped")
state_trs=tableArea.find_all('tr')
for tr in state_trs:
title_node=state_trs.find_all('td')
print title_node.get_text()