为什么正确输入代码后运行结果是空白呢？
from urllib.request import urlopen
from bs4 import BeautifulSoup as bs
import re
resp = urlopen("https://en.wikipedia.org/wiki/Main_Page").read().decode("utf-8")
soup = bs(resp,"html.parser")
listUrls = soup.findAll("a", herf=re.compile("^/wiki/"))
for url in listUrls:
print(url["herf"])
