为什么我不能在python中下载这个网页?

时间:2011-11-08 06:55:47

标签: python http url curl download

请亲自试试:)!

curl http://www.windowsphone.com/en-US/apps?list=free

结果是:

    <html><head><title>Object moved</title></head><body>
<h2>Object moved to <a href="https://login.live.com/login.srf?wa=wsignin1.0&amp;rpsnv=11&amp;checkda=1&amp;ct=1320735308&amp;rver=6.1.6195.0&amp;wp=MBI&amp;wreply=http:%2F%2Fwww.windowsphone.com%2Fen-US%2Fapps%3Flist%3Dfree&amp;lc=1033&amp;id=268289">here</a>.</h2>
</body></html>

def download(source_url):
    try:
        socket.setdefaulttimeout(10)        
        agents = ['Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0)','Mozilla/4.0 (compatible; MSIE 7.0b; Windows NT 5.1)','Microsoft Internet Explorer/4.0b1 (Windows 95)','Opera/8.00 (Windows NT 5.1; U; en)']
        ree = urllib2.Request(source_url)
        ree.add_header('User-Agent',random.choice(agents))
        resp = urllib2.urlopen(ree)
        htmlSource = resp.read()
        return htmlSource
    except Exception, e:
        print e
        return ""

download('http://www.windowsphone.com/en-US/apps?list=free')

结果是:

<html><head><meta http-equiv="REFRESH" content="0; URL=http://www.windowsphone.com/en-US/apps?list=free"><script type="text/javascript">function OnBack(){}</script></head></html>

我想下载网页的实际来源。

2 个答案:

答案 0 :(得分:3)

失败的原因是因为http://www.windowsphone.com尝试设置一个cookie,在https://login.live.com上检查该cookie会创建另一个cookie并在成功时重定向回windowsphone.com。

您应该查看http://docs.python.org/library/cookielib.html

如果你想使用curl,允许它创建一个像这样的cookie文件:

curl -so /dev/null 'http://www.windowsphone.com/en-US/apps?list=free' -c 'myCookieJar'

在你的shell中运行more myCookieJar,你会看到类似这样的内容:

# Netscape HTTP Cookie File
# http://www.netscape.com/newsref/std/cookie_spec.html
# This file was generated by libcurl! Edit at your own risk.

.www.windowsphone.com   TRUE    /       FALSE   0       WPMSLSS SLSS=1
login.live.com  FALSE   /       FALSE   0       MSPRequ lt=1320738008&co=1&id=268289

运行(注意'myCookieJar'之前的-b选项):

curl -so 'windowsphone.html' 'http://www.windowsphone.com/en-US/apps?list=free' -b 'myCookieJar'

并且您将在浏览器中看到的文件windowsphone.html中获取该页面的内容。

答案 1 :(得分:2)

Flesk真的有这个答案(+1)。

调试HTTP连接的另一种直接方式是Netcat,它基本上是一个强大的telnet实用程序。

因此,假设您要调试HTTP请求中正在发生的事情:

$ nc www.windowsphone.com 80
GET /en-US/apps?list=free HTTP/1.0
Host: www.windowsphone.com
User-Agent: Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0)

这会将请求标头发送到服务器(您需要按回车键两次才能发送)。

之后,服务器将响应:

HTTP/1.1 302 Found
Location: https://login.live.com/login.srf?wa=wsignin1.0&rpsnv=11&checkda=1&ct=1320745265&rver=6.1.6195.0&wp=MBI&wreply=http:%2F%2Fwww.windowsphone.com%2Fen-US%2Fapps%3Flist%3Dfree&lc=1033&id=268289
Server: Microsoft-IIS/7.5
Set-Cookie: WPMSLSS=SLSS=1; domain=www.windowsphone.com; path=/; HttpOnly
X-Powered-By: ASP.NET
X-Server: SN2CONXWWBA06
Date: Tue, 08 Nov 2011 09:41:05 GMT
Connection: close
Content-Length: 337

<html><head><title>Object moved</title></head><body>
<h2>Object moved to <a href="https://login.live.com/login.srf?wa=wsignin1.0&amp;rpsnv=11&amp;checkda=1&amp;ct=1320745265&amp;rver=6.1.6195.0&amp;wp=MBI&amp;wreply=http:%2F%2Fwww.windowsphone.com%2Fen-US%2Fapps%3Flist%3Dfree&amp;lc=1033&amp;id=268289">here</a>.</h2>
</body></html>

因此服务器返回302,这是重定向的HTTP状态代码,从而提示“浏览器”打开位置标头中传递的URL。

Netcat是一个很好的调试和跟踪各种网络通信的工具,当我想深入研究HTTP协议时,它对我帮助很大。