我想到了两种方案：

1）从whois查询网站上抓取，例如http://whois.chinaz.com。

2）从whois命令行查询工具的结果中获取。Windows下的whois命令行工具 whois.exe： http://www.everbox.com/f/Mpe2uCBvbregnCPn33h8W2LLBv

这两种方案都能跨平台。

下面给出我的解决方案，优先采用1），如果查询失败再尝试2）：

def whois(self, url, timeout=10):
        """Query whois info
        Compatible with windows
        Note:
        On unix please install whois first.
        On windows please download whois.exe from http://technet.microsoft.com/en-us/sysinternals/bb897435.aspx, then place it in Python directory e.g. C:\Python27
        """
        domain = common.get_domain(url)
        if domain:
            key = 'whos_%s' % domain
            try:
                text = self.cache[key]
                if text:
                    return text
            except KeyError:
                pass
            
            # try http://whois.chinaz.com/ first
            query_url = 'http://whois.chinaz.com/%s' % domain
            html = self.get(query_url)
            if html:
                m = re.compile("").search(html)
                if m:
                    script_url = urljoin(query_url, m.groups()[0])
                    text = self.get(script_url)
                    if not text or not '@' in text:
                        del self.cache[query_url]
                        del self.cache[script_url]
                        
                        # try whois command
                        r = subprocess.Popen(['whois', domain], stdout=subprocess.PIPE)
                        start = time.time()
                        while r.poll() == None:
                            time.sleep(0.5)
                            if time.time() - start > timeout:
                                try:
                                    r.kill()
                                except Exception, e:
                                    pass
                                break
                        if r.poll() !=1:
                            text = r.communicate()[0]
       
                    if text and '@' in text:
                        self.cache[key] = text
                        return text