目标：
我们解析百度首页的logo
bs_baidu_logo.py
from urllib.request import urlopen
from bs4 import BeautifulSoup
html = urlopen("http://www.baidu.com")
bsObj = BeautifulSoup(html.read(), "html.parser")
print(bsObj.img)
运行结果:
<img height="129" hidefocus="true" src="//www.baidu.com/img/bd_logo1.png" width="270"/>