title: Troubleshooting "ssl certificate verify failed" error
body: <p>On Windows Vista SP2 + Python 2.7.10 I can connect to <a href="https://www.python.org" rel="nofollow">https://www.python.org</a>, but not to <a href="https://codereview.appspot.com" rel="nofollow">https://codereview.appspot.com</a></p>
  
  <p>The script:</p>
  
  <pre><code>HOST1 = 'https://www.python.org'
  HOST2 = 'https://codereview.appspot.com'
  
  import urllib2
  print HOST1
  urllib2.urlopen(HOST1)
  print HOST2
  urllib2.urlopen(HOST2)
  </code></pre>
  
  <p>And the output:</p>
  
  <pre><code>E:\&gt;py test.py
  https://www.python.org
  https://codereview.appspot.com
  Traceback (most recent call last):
    File "test.py", line 9, in &lt;module&gt;
      urllib2.urlopen(HOST2)
    File "C:\Python27\lib\urllib2.py", line 158, in urlopen
      return opener.open(url, data, timeout)
    File "C:\Python27\lib\urllib2.py", line 435, in open
      response = self._open(req, data)
    File "C:\Python27\lib\urllib2.py", line 453, in _open
      '_open', req)
    File "C:\Python27\lib\urllib2.py", line 413, in _call_chain
      result = func(*args)
    File "C:\Python27\lib\urllib2.py", line 1244, in https_open
      context=self._context)
    File "C:\Python27\lib\urllib2.py", line 1201, in do_open
      raise URLError(err)
  urllib2.URLError: &lt;urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:590)&gt;
  </code></pre>
  
  <p>How can I troubleshoot, what exactly is wrong with <a href="https://codereview.appspot.com/" rel="nofollow">https://codereview.appspot.com/</a> ?</p>