python - 使用 Python 的请求发送 ASP.net POST

Question

我正在使用 Python 的请求模块抓取旧的 ASP.net 网站。

我花了 5 个多小时试图弄清楚如何模拟此 POST 请求，但无济于事。按照我下面的方式进行操作，我基本上收到一条消息说“没有项目与该项目引用相匹配。”

任何帮助将不胜感激 - 这是请求和我的代码，出于对简洁和/或隐私的尊重，对一些内容进行了修改:

我自己的代码:

import requests

# Scraping the item number from the website, I have confirmed this is working.

#Then use the newly acquired item number to request the data.
item_url = http://www.example.com/EN/items/Pages/yourrates.aspx?vr= + item_number[0]
viewstate = r'/wEPD...' # Truncated for brevity.

# Create the appropriate request and payload.
payload = {"vr": int(item_number[0])}

item_request_body = {
        "__SPSCEditMenu": "true",
        "MSOWebPartPage_PostbackSource": "",
        "MSOTlPn_SelectedWpId": "",
        "MSOTlPn_View": 0,
        "MSOTlPn_ShowSettings": "False",
        "MSOGallery_SelectedLibrary": "",
        "MSOGallery_FilterString": "",
        "MSOTlPn_Button": "none",
        "__EVENTTARGET": "",
        "__EVENTARGUMENT": "",
        "MSOAuthoringConsole_FormContext": "",
        "MSOAC_EditDuringWorkflow": "",
        "MSOSPWebPartManager_DisplayModeName": "Browse",
        "MSOWebPartPage_Shared": "",
        "MSOLayout_LayoutChanges": "",
        "MSOLayout_InDesignMode": "",
        "MSOSPWebPartManager_OldDisplayModeName": "Browse",
        "MSOSPWebPartManager_StartWebPartEditingName": "false",
        "__VIEWSTATE": viewstate,
        "keywords": "Search our site",
        "__CALLBACKID": "ctl00$SPWebPartManager1$g_dbb9e9c7_fe1d_46df_8789_99a6c9db4b22",
        "__CALLBACKPARAM": "startvr"
    }

# Write the appropriate headers for the property information.
item_request_headers = {
    "Host": home_site,
    "Connection": "keep-alive",
    "Content-Length": len(encoded_valuation_request),
    "Cache-Control": "max-age=0",
    "Origin": home_site,
    "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.125 Safari/537.36",
    "Content-Type": "application/x-www-form-urlencoded; charset=UTF-8",
    "Cookie": "__utma=48409910.1174413745.1405662151.1406402487.1406407024.17; __utmb=48409910.7.10.1406407024; __utmc=48409910; __utmz=48409910.1406178827.13.3.utmcsr=ratesandvallandingpage|utmccn=landingpages|utmcmd=button",
    "Accept": "*/*",
    "Referer": valuation_url,
    "Accept-Encoding": "gzip,deflate,sdch",
    "Accept-Language": "en-US,en;q=0.8"
}

    response = requests.post(url=item_url, params=payload, data=item_request_body, headers=item_request_headers)
    print response.text

Chrome 告诉我请求的内容如下:

Remote Address:202.55.96.131:80
Request URL:http://www.example.com/EN/items/Pages/yourrates.aspx?vr=123456789
Request Method:POST
Status Code:200 OK

Request Headers
Accept:*/*
Accept-Encoding:gzip,deflate,sdch
Accept-Language:en-US,en;q=0.8
Cache-Control:max-age=0
Connection:keep-alive
Content-Length:21501
Content-Type:application/x-www-form-urlencoded; charset=UTF-8
Cookie:__utma=48409910.1174413745.1405662151.1406402487.1406407024.17; __utmb=48409910.7.10.1406407024; __utmc=48409910; __utmz=48409910.1406178827.13.3.utmcsr=ratesandvallandingpage|utmccn=landingpages|utmcmd=button
Host:www.site.com
Origin:www.site.com
Referer:http://www.example.com/EN/items/Pages/yourrates.aspx?vr=123456789
User-Agent:Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.125 Safari/537.36

Query String Parameters
vr:123456789

Form Data
__SPSCEditMenu:true
MSOWebPartPage_PostbackSource:
MSOTlPn_SelectedWpId:
MSOTlPn_View:0
MSOTlPn_ShowSettings:False
MSOGallery_SelectedLibrary:
MSOGallery_FilterString:
MSOTlPn_Button:none
__EVENTTARGET:
__EVENTARGUMENT:
MSOAuthoringConsole_FormContext:
MSOAC_EditDuringWorkflow:
MSOSPWebPartManager_DisplayModeName:Browse
MSOWebPartPage_Shared:
MSOLayout_LayoutChanges:
MSOLayout_InDesignMode:
MSOSPWebPartManager_OldDisplayModeName:Browse
MSOSPWebPartManager_StartWebPartEditingName:false
__VIEWSTATE:/wEPD...(Omitted for length)
keywords:Search our site
__CALLBACKID:ctl00$SPWebPartManager1$g_dbb9e9c7_fe1d_46df_8789_99a6c9db4b22
__CALLBACKPARAM:startvr

Answer 1

你的请求参数太多，不应该设置content-type、content-length、host、origin或connection headers； 将这些留给请求来设置。

您还加倍了 url 参数；手动将 vr 参数添加到 URL 中，或使用 params，但不要同时执行这两项操作。

很可能 POST 正文中的某些参数是由绑定(bind)到 session 的 ASP 应用程序生成的。我会使用带有 Session object 的 GET 请求valuation_url，解析该页面中的表单以提取 __CALLBACKID 参数。然后，请求 Session 将存储服务器设置的任何 cookie 并重用它们:

item_request_headers = {
    "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.125 Safari/537.36",
    "Accept": "*/*",
    "Accept-Encoding": "gzip,deflate,sdch",
    "Accept-Language": "en-US,en;q=0.8"
}
payload = {"vr": int(item_number[0])}

session = requests.Session(headers=item_request_headers)

# Get form page
form_response = session.get(validation_url, params=payload) 

# parse form page; BeautifulSoup could do this for example
soup = BeautifulSoup(form_response.content)
callbackid = soup.select('input[name=__CALLBACKID]')[0]['value']

item_request_body = {
    "__SPSCEditMenu": "true",
    "MSOWebPartPage_PostbackSource": "",
    "MSOTlPn_SelectedWpId": "",
    "MSOTlPn_View": 0,
    "MSOTlPn_ShowSettings": "False",
    "MSOGallery_SelectedLibrary": "",
    "MSOGallery_FilterString": "",
    "MSOTlPn_Button": "none",
    "__EVENTTARGET": "",
    "__EVENTARGUMENT": "",
    "MSOAuthoringConsole_FormContext": "",
    "MSOAC_EditDuringWorkflow": "",
    "MSOSPWebPartManager_DisplayModeName": "Browse",
    "MSOWebPartPage_Shared": "",
    "MSOLayout_LayoutChanges": "",
    "MSOLayout_InDesignMode": "",
    "MSOSPWebPartManager_OldDisplayModeName": "Browse",
    "MSOSPWebPartManager_StartWebPartEditingName": "false",
    "__VIEWSTATE": viewstate,
    "keywords": "Search our site",
    "__CALLBACKID": callbackid,
    "__CALLBACKPARAM": "startvr"
}

item_url = 'http://www.example.com/EN/items/Pages/yourrates.aspx'

response = session.post(url=item_url, params=payload, data=item_request_body,
                        headers={'Referer': form_response.url})

session 处理 header (设置用户代理和接受参数)，只有在 session 的 POST 上我们才会添加引用 header 。