爬虫问题

源代码:
import requests
from bs4 import BeautifulSoup
url="https://fs.lianjia.com/zufang/"
r=requests.get(url)
print(r)
print(r.text)
s=BeautifulSoup(r.text)
print(s,"html.parser")
s.find_all("div",class_="")

错误:
Warning (from warnings module):
  File "C:\Users\Administrator\Desktop\python\11.21 01.py", line 7
    s=BeautifulSoup(r.text)
GuessedAtParserWarning: No parser was explicitly specified, so I'm using the best available HTML parser for this system ("html.parser"). This usually isn't a problem, but if you run this code on another system, or in a different virtual environment, it may use a different parser and behave differently.

The code that caused this warning is on line 7 of the file C:\Users\Administrator\Desktop\python\11.21 01.py. To get rid of this warning, pass the additional argument 'features="html.parser"' to the BeautifulSoup c**tructor.

对不起,发错了

这个才是
源代码:
import requests
from bs4 import BeautifulSoup
url="https://dg.lianjia.com/"
r=requests.get(url)
print(r)
print(r.text)
s=BeautifulSoup(r.text,"html.parser")
print(s,"html.parser")
s.find_all("div",class_="")
s.find_all("div",class_="pic-panel")
links_div=s.find_all("div",class_="pic-panel")
links=[div.a.get("href") for div in links_div]
print(links)
为什么结果是[]?

找不到class_="pic-panel"