python - urllib2， Mechanize 返回的结果与浏览器不同 - 还有什么可以欺骗的？

Question

我正在尝试创建一个脚本(纯粹是学习目的)来用几个不同的词典翻译给定的单词。我完成了两个工作，使用 urllib2 和 beautifulsoup 来获取和解析翻译，然后转向谷歌翻译。

我很快发现它返回 403 禁止错误。添加用户代理即可获得翻译，但只有一个单词的翻译。为了说明这一点，请转到http://translate.google.com/?text=test&sl=en&tl=es您将获得翻译(在名为“hps”的类(class)中)以及动词、名词和形容词的列表。但是使用下面的脚本和 html 是不同的，仅返回主要翻译，并且在

span id=result_box

找不到动词、名词等。

在这个过程中，通过大量的谷歌搜索，我意识到现在有一​​个 API - 而且不是免费的。我不打算发布任何最终脚本，也不打算用它来违反任何 TOS，但我现在最感兴趣的是为什么浏览器和 urllib 等之间存在差异。

为此，我尝试了带有用户代理的纯 urllib2，并进行了 Mechanize - 如下所示。所以，我的问题是 - 除了用户代理之外，浏览器和 python 脚本还有什么区别？我尝试过使用 Firebug ，但没有任何东西跳到我身上(尽管我是一个菜鸟)。谢谢!

编辑:来自 firebug 的请求 header 和我的脚本如下。

import mechanize
import re
import cookielib

# Browser
br = mechanize.Browser()

# Cookie Jar
cj = cookielib.LWPCookieJar()
br.set_cookiejar(cj)

# Browser options
br.set_handle_equiv(True)
br.set_handle_redirect(True)
br.set_handle_referer(True)
br.set_handle_robots(False)

# Follows refresh 0 but not hangs on refresh > 0
br.set_handle_refresh(mechanize._http.HTTPRefreshProcessor(), max_time=1)

# Want debugging messages?
br.set_debug_http(True)
br.set_debug_redirects(True)
br.set_debug_responses(True)

# User-Agent (this is cheating, ok?)
br.addheaders = [('User-agent', 'Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.1) Gecko/2008071615 Fedora/3.0.1-1.fc9 Firefox/3.0.1')]

# Open some site, let's pick a random one, the first that pops in mind:
r = br.open('http://translate.google.com/?text=test&sl=en&tl=es')
html = r.read()
match = re.findall(r'verb', html)

print match

Firebug :

GET /?text=test&sl=en&tl=es HTTP/1.1

Accept  text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Charset  ISO-8859-1,utf-8;q=0.7,*;q=0.7
Accept-Encoding gzip, deflate
Accept-Language en-us,en;q=0.5
Connection  keep-alive
Cookie  PREF=ID=298b435815ef8553:U=e7dad4baf65f083b:FF=0:LD=en:CR=2:TM=1327516863:LM=1339428154:S=maktYFZEHXXpMDFg; NID=60=U229h4lzOnjpHyidbhgYecCx72Myp_-XHgupW-R_mWtpuOveDdIOO1uLBq-6ltn-ER15ppJryR7yYOYEhkCfUCl45qNz5aymBQ1CGDHS4UcHu2oIDYAHut0ctnlL76eDW3n7kjOWoz5wNH6NMw
Host    translate.google.com
User-Agent  Mozilla/5.0 (Windows NT 6.1; WOW64; rv:9.0) Gecko/20100101 Firefox/9.0

脚本:

send: 'GET /?text=test&sl=en&tl=es HTTP/1.1\r\nAccept-Encoding: identity\r\nHost: translate.google.com\r\nConnection: close\r\nUser-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.1) Gecko/2008071615 Fedora/3.0.1-1.fc9 Firefox/3.0.1\r\n\r\n' reply: 'HTTP/1.1 200 OK\r\n' header: Date: Mon, 11 Jun 2012 16:13:42 GMT

header: Expires: Fri, 01 Jan 1990 00:00:00 GMT

header: Cache-Control: no-cache, must-revalidate

header: Pragma: no-cache

header: X-Frame-Options: SAMEORIGIN

header: Content-Type: text/html; charset=UTF-8

header: Content-Language: en

header: Set-Cookie: PREF=ID=6dd42f2264250d7c:TM=1333431222:LM=1339454222:S=k6JXSoGGaAMNmPEo; expires=Wed, 11-Jun-2014 16:13:42 GMT; path=/; domain=.google.com

header: Set-Cookie: NID=60=f8czmR413h3sKUGJUUM4PLKl2O7SUtqfW5hss5O54sRKoErf9wIEU4Wu2WCuHzWTJQ3p1Rj7dQv1B4BBmSMY1tmfus7UZGCYFIKaXoKwklZ9tZsr5vds8vvvFjRdZyevn; expires=Tue, 11-Dec-2012 16:13:42 GMT; path=/; domain=.google.com; HttpOnly

header: P3P: CP="This is not a P3P policy! See http://www.google.com/support/accounts/bin/answer.py?hl=en&answer=151657 for more info."

header: X-Content-Type-Options: nosniff

header: Server: HTTP server (unknown)

header: X-XSS-Protection: 1; mode=block

header: Connection: close

Answer 1

未找到动词、形容词，因为它们是通过 AJAX 调用加载的。您的 mechanize 浏览器没有 JavaScript。因此它无法执行任何 AJAX。但是，如果您可以查看浏览器的检查器或其他东西，您将看到调用的 header 、URL 和参数。现在剩下要做的就是模仿调用。

我 curl 了它，我得到了一个 JSON 响应:

thrustmaster@thrustmaster:~/Temp$ curl 'http://translate.google.com/translate_a/t?client=t&text=test&hl=en&sl=en&tl=es&multires=1&ssel=0&tsel=0&sc=1' -H 'User-Agent: blah'
[[["prueba","test","",""]],[["noun",["prueba","ensayo","test","examen","an�lisis","criterio","toque","ejercicio","tanteo"],[["prueba",["test","proof","evidence","trial","event","race"]],["ensayo",["test","trial","essay","assay","testing","rehearsal"]],["test",["test"]],["examen",["examination","review","exam","test","inspection","quiz"]],["an�lisis",["analysis","test","review","assay","breakdown"]],["criterio",["criterion","judgment","standard","test","view","yardstick"]],["toque",["touch","stroke","test","knock","blast","chime"]],["ejercicio",["exercise","practice","drill","practicing","test","prosecution"]],["tanteo",["score","scoring","trial","test","try","calculation"]]]],["adjective",["de prueba"],[["de prueba",["test","testing","trial","probationary","corrective"]]]],["verb",["probar","comprobar","ensayar","examinar","poner a prueba","experimentar","someter a prueba","interrogar","hacer investigaciones","justificar","graduar"],[["probar",["test","try","prove","taste","try out","sample"]],["comprobar",["check","test","prove","ascertain","make sure","substantiate"]],["ensayar",["test","try","rehearse","try out","assay","essay"]],["examinar",["examine","consider","review","look at","explore","test"]],["poner a prueba",["test","try","try out","prove","tempt","put through his paces"]],["experimentar",["experience","experiment","undergo","experiment with","feel","test"]],["someter a prueba",["test","try out","touch"]],["interrogar",["question","interrogate","examine","cross-examine","ask","test"]],["hacer investigaciones",["test"]],["justificar",["justify","warrant","substantiate","prove","make good","test"]],["graduar",["graduate","grade","calibrate","time","test"]]]]],"en",,[["prueba",[5],1,0,1000,0,1,0]],[["test",4,,,""],["test",5,[["prueba",1000,1,0],["prueba de",0,1,0],["ensayo",0,1,0],["de prueba",0,1,0],["test",0,1,0]],[[0,4]],"test"]],,,[["en"]],5]thrustmaster@thrustmaster:~/Temp$ 

现在，可能在您的脚本中，您必须从以下 URL 获取响应:

http://translate.google.com/translate_a/t?client=t&text=test&hl=en&sl=en&tl=es&multires=1&ssel=0&tsel=0&sc=1

附注:

正如您所说，如果您计划使用此脚本，这可能是 TOS 问题。在 API 上使用它始终是更好的选择。您所依赖的 HTML 可以随时更改。