如何使用python从列表中抓取url

Question

我想抓取列表中的网址。基本上我正在抓取一个网站，我正在从中抓取一个链接，我正在寻找特定的链接 抓取这些链接，然后我搜索另一个特定的链接并抓取它。 我的代码：

from bs4 import BeautifulSoup
import urllib.request
import re
r = urllib.request.urlopen('http://i.cantonfair.org.cn/en/ExpExhibitorList.aspx?k=glassware')
soup = BeautifulSoup(r, "html.parser")
links = soup.find_all("a", href=re.compile(r"expexhibitorlist\.aspx\?categoryno=[0-9]+"))
linksfromcategories = ([link["href"] for link in links])

string = "http://i.cantonfair.org.cn/en/"
linksfromcategories = [string + x for x in linksfromcategories]
subcatlinks = list()
for link in linksfromcategories:
  response = urllib.request.urlopen(link)
  soup2 = BeautifulSoup(response, "html.parser")
  links2 = soup2.find_all("a", href=re.compile(r"ExpExhibitorList\.aspx\?categoryno=[0-9]+"))
  linksfromsubcategories = ([link["href"] for link in links2])
  subcatlinks.append(linksfromsubcategories)
responses = urllib.request.urlopen(subcatlinks)
soup3 = BeautifulSoup(responses, "html.parser")
print (soup3)

我得到了错误

Traceback (most recent call last):
  File "D:\python\phase2.py", line 46, in <module>
    responses = urllib.request.urlopen(subcatlinks)
  File "C:\Users\amanp\AppData\Local\Programs\Python\Python35-32\lib\urllib\request.py", line 162, in urlopen
    return opener.open(url, data, timeout)
  File "C:\Users\amanp\AppData\Local\Programs\Python\Python35-32\lib\urllib\request.py", line 456, in open
    req.timeout = timeout
AttributeError: 'list' object has no attribute 'timeout'

Answer 1

您一次只能将一个链接传递给urllib.request.urlopen，而不是一整个列表。

所以你需要另一个这样的循环：

for link in subcatlinks:
    response = urllib.request.urlopen(link)
    soup3 = BeautifulSoup(response, "html.parser")
    print(soup3)