python，urllib2，因 404 错误而崩溃

Question

我有一个程序可以从存储在数据库中的 url 中获取内容。我正在使用 beautifulsoup 和 urllib2 来抓取内容。当我输出结果时，我发现程序在遇到(看起来像)403 错误时崩溃了。那么如何防止我的程序因 403/404 等错误而崩溃？

相关输出:

Traceback (most recent call last):
  File "web_content.py", line 29, in <module>
    grab_text(row) 
  File "web_content.py", line 21, in grab_text
    f = urllib2.urlopen(row)
  File "/usr/lib/python2.7/urllib2.py", line 126, in urlopen
    return _opener.open(url, data, timeout)
  File "/usr/lib/python2.7/urllib2.py", line 400, in open
    response = meth(req, response)
  File "/usr/lib/python2.7/urllib2.py", line 513, in http_response
    'http', request, response, code, msg, hdrs)
  File "/usr/lib/python2.7/urllib2.py", line 438, in error
    return self._call_chain(*args)
  File "/usr/lib/python2.7/urllib2.py", line 372, in _call_chain
    result = func(*args)
  File "/usr/lib/python2.7/urllib2.py", line 521, in http_error_default
    raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)
urllib2.HTTPError: HTTP Error 403: Forbidden

Answer 1

你可以用try/except包围请求，例如

try:
    urllib2.openurl(url)
except urllib2.HTTPError, e:
    print e

参见 http://www.voidspace.org.uk/python/articles/urllib2.shtml#handling-exceptions一些很好的例子和信息。