import requestsfrom bs4 import BeautifulSoupurl = 'http://www.zuihaodaxue.com/zuihaodaxuepaiming2017.html'def gethtml(url):    # 打开网页有风险，需要使用try-except语句进行风险控制    kv = {'user-agent':'Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:54.0) Gecko/20100101 Firefox/54.0'}    try:        r = requests.get(url,headers=kv)        r.raise_for_status()   # 如果打开失败，则会抛出一个HttpError异常        # encoding是从header中分析出来的编码方式，apparent_encoding是 从内容分析出的编码方式        r.encoding=r.apparent_encoding        return r    except:        print("打开失败")        return -1def gettext(r):    soup = BeautifulSoup(r.text,'html.parser')    #print(soup.prettify())    tr = soup('tr')    ls = list()    lst = list()    for i in range(4):        th = tr[0]('th')        lst.append(th[i].string)    ls.append(lst)    for i in range(1,len(tr)):        td = tr[i]('td')        lst=list()        lst.append(i)        for k in range(1,4):            lst.append(td[k].string)        ls.append(lst)    return lsdef printtext(ls):    for i in ls:         print('{0:^10}\t{1:{3}^10}\t{2:^10}'.format(i[0],i[1],i[2],chr(12288)))if __name__ =='__main__':    r = gethtml(url)    ls = gettext(r)    printtext(ls)