python - urllib.urlopen 有效，但 urllib2.urlopen 无效

Question

我有一个正在测试的简单网站。它在本地主机上运行，​​我可以在我的网络浏览器中访问它。索引页就是简单的“运行”二字。 urllib.urlopen 将成功读取页面，但 urllib2.urlopen 不会。这是演示问题的脚本(这是实际脚本，而不是不同测试脚本的简化):

import urllib, urllib2
print urllib.urlopen("http://127.0.0.1").read()  # prints "running"
print urllib2.urlopen("http://127.0.0.1").read() # throws an exception

这是堆栈跟踪:

Traceback (most recent call last):
  File "urltest.py", line 5, in <module>
    print urllib2.urlopen("http://127.0.0.1").read()
  File "C:\Python25\lib\urllib2.py", line 121, in urlopen
    return _opener.open(url, data)
  File "C:\Python25\lib\urllib2.py", line 380, in open
    response = meth(req, response)
  File "C:\Python25\lib\urllib2.py", line 491, in http_response
    'http', request, response, code, msg, hdrs)
  File "C:\Python25\lib\urllib2.py", line 412, in error
    result = self._call_chain(*args)
  File "C:\Python25\lib\urllib2.py", line 353, in _call_chain
    result = func(*args)
  File "C:\Python25\lib\urllib2.py", line 575, in http_error_302
    return self.parent.open(new)
  File "C:\Python25\lib\urllib2.py", line 380, in open
    response = meth(req, response)
  File "C:\Python25\lib\urllib2.py", line 491, in http_response
    'http', request, response, code, msg, hdrs)
  File "C:\Python25\lib\urllib2.py", line 418, in error
    return self._call_chain(*args)
  File "C:\Python25\lib\urllib2.py", line 353, in _call_chain
    result = func(*args)
  File "C:\Python25\lib\urllib2.py", line 499, in http_error_default
    raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)
urllib2.HTTPError: HTTP Error 504: Gateway Timeout

有什么想法吗？我可能最终需要 urllib2 的一些更高级的功能，所以我不想只求助于使用 urllib，而且我想了解这个问题。

Answer 1

听起来您定义了 urllib2 正在使用的代理设置。当它尝试代理“127.0.0.01/”时，代理放弃并返回 504 错误。

来自 Obscure python urllib2 proxy gotcha :

proxy_support = urllib2.ProxyHandler({})
opener = urllib2.build_opener(proxy_support)
print opener.open("http://127.0.0.1").read()

# Optional - makes this opener default for urlopen etc.
urllib2.install_opener(opener)
print urllib2.urlopen("http://127.0.0.1").read()