python BS4获取href网址

from bs4 import BeautifulSoup
# what does Thread means
from threading import Thread
import urllib.request

#Location of restaurants
home_url="https://www.yelp.com"
find_what="Restaurants"
location="London"

#Get all restaurants that match the search criteria
#https://www.yelp.com/search?find_desc=Restaurants&find_loc=London
search_url="https://www.yelp.com/search?find_desc=" +find_what+"&find_loc="+location
s_html= urllib.request.urlopen(search_url).read() #urlopen(search_url).read()
print("here")
soups_s=BeautifulSoup(s_html,"lxml")

#Get URLs of top 10 Restaurants in London
s_urls=soups_s.select(‘.biz-name‘[:10])
print(len(s_urls))
print(s_urls)
url=[]
print(type(s_urls))
print(type(s_urls[0]))
print(s_urls[0])
print(s_urls[0][‘href‘])
for u in range(len(s_urls)):
    url.append(home_url+s_urls[u][‘href‘])
#https://www.yelp.com/biz/duck-and-waffle-london-3?osq=Restaurants
print(url)
#Function that will do actual scraping job
def scrape(ur):
    html=urllib.request.urlopen(ur).read()
    soup=BeautifulSoup(html,"lxml")

    title=soup.select(‘.biz-page-title‘)
    saddress=soup.select(‘.street-address‘)
    phone=soup.select(‘.biz-phone‘)

    if title:
        print("Title:",title[0].getText().strip())
    if saddress:
        print("Streeet Address:",saddress[0].getText().strip())
    if phone:
        print("Phone number:",phone[0].getText().strip())
    print("---------------------")
    threadlist=[]
    i=0
    #Making thereads to perform scraping
    while(i<len(url)):
        t=Thread(target=scrape,args=(url[i],))
        t.start()
        threadlist.append(t)
        i=i+1
    for t in threadlist:
        t.join()