python - 使用python访问网页内容

Question

我正在尝试访问和操作网页的数据。 出于主要测试目的，我使用了 w3schools 网站，但我无法使用以下代码访问内容:

import urllib as url
import xml.etree.ElementTree as et

web_data = url.urlopen("www.w3schools.com/xml/cd_catalog.xml")
str_data = web_data.read()
print str_data

这些是我遇到的错误:

Traceback (most recent call last):
  File "C:\Python27\webpage.htlm.py", line 4, in <module>
    web_data = url.urlopen("www.w3schools.com/xml/cd_catalog.xml")
  File "C:\Python27\lib\urllib.py", line 87, in urlopen
    return opener.open(url)
  File "C:\Python27\lib\urllib.py", line 213, in open
    return getattr(self, name)(url)
  File "C:\Python27\lib\urllib.py", line 469, in open_file
    return self.open_local_file(url)
  File "C:\Python27\lib\urllib.py", line 483, in open_local_file
    raise IOError(e.errno, e.strerror, e.filename)
IOError: [Errno 2] The system cannot find the path specified: 'www.w3schools.com\\xml\\cd_catalog.xml'

Answer 1

URL 以协议(protocol)开头。

在这里，您可能需要 http://www.w3schools.com/xml/cd_catalog.xml。