python3大学排名，list index out of range。

import requests
import bs4
from bs4 import BeautifulSoup
allUniv = []
def getHTMLTEXT(url):
    try:
        r = requests.get(url,timeout=30)
        r.raise_for_status()
        r.encoding = "utf-8"
        return r.text
    except:
        return ""
def fillUnivList(soup):
    data = soup.find_all("tr")
    for tr in data:
        ltd = tr.find_all("td")
        if len(ltd)==0:
            continue
        singleUniv = []
        for td in ltd:
            singleUniv.append(td.string)
        allUniv.append(singleUniv)
def printUnivList(num):
   
```python



``` print("{:^4}{:^10}{:^5}{:^8}{:^10}".format
    ("排名","学校名称","省市","总分","办学层次"))
    for i in range(num):
            u = allUniv[i]      这里报错list index out of range。
    for i in range(num):
        if i is None:
            i = 0
        print("{:^4}{:^10}{:^5}{:^8}{:^10}".format
        (u[0],u[1],u[2],u[4],u[5]))
def main(num):
    url = "https://www.shanghairanking.cn/rankings/bcur/2022"
    html = getHTMLTEXT(url)
    soup = BeautifulSoup(html,"html.parser")
    fillUnivList(soup)
    printUnivList(num)
main(5)

td.string ==> td.text.strip()


 排名    学校名称    省市     总分      办学层次   
 1  清华大学    Tsinghua University   双一流/985/211 北京   999.4     37.6   
 2  北京大学    Peking University   双一流/985/211 北京   912.5     34.4   
 3  浙江大学    Zhejiang University   双一流/985/211 浙江   825.3     34.1   
 4  上海交通大学    Shanghai Jiao Tong University   双一流/985/211 上海   783.3     35.5   
 5  复旦大学    Fudan University   双一流/985/211 上海   697.8     35.9   

我看了一下，allUniv为空，所以越界了