Python 请求 - 是否可以在 HTTP POST 后收到部分响应？

Question

我正在使用 Python Requests Module对网站进行数据挖掘。作为数据挖掘的一部分，我必须通过 HTTP POST 表单并通过检查生成的 URL 来检查它是否成功。我的问题是，在 POST 之后，是否可以请求服务器不发送整个页面？我只需要检查 URL，但我的程序下载了整个页面并消耗了不必要的带宽。代码很简单

import requests
r = requests.post(URL, payload)
if 'keyword' in r.url:
   success
fail

Answer 1

一个简单的解决方案，如果它对您来说是可行的。就是走低级。使用套接字库。 例如，您需要发送一个正文中包含一些数据的 POST。我在一个站点的爬虫中使用了它。

import socket
from urllib import quote # POST body is escaped. use quote

req_header = "POST /{0} HTTP/1.1\r\nHost: www.yourtarget.com\r\nUser-Agent: For the lulz..\r\nContent-Type: application/x-www-form-urlencoded; charset=UTF-8\r\nContent-Length: {1}"
req_body = quote("data1=yourtestdata&data2=foo&data3=bar=")
req_url = "test.php"
header = req_header.format(req_url,str(len(req_body))) #plug in req_url as {0} 
                                                       #and length of req_body as Content-length
s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)   #create a socket
s.connect(("www.yourtarget.com",80))                   #connect it
s.send(header+"\r\n\r\n"+body+"\r\n\r\n")              # send header+ two times CR_LF + body + 2 times CR_LF to complete the request

page = ""
while True:
    buf = s.recv(1024) #receive first 1024 bytes(in UTF-8 chars), this should be enought to receive the header in one try
    if not buf:
        break
    if "\r\n\r\n" in page: # if we received the whole header(ending with 2x CRLF) break
        break
    page+=buf
s.close()       # close the socket here. which should close the TCP connection even if data is still flowing in
                # this should leave you with a header where you should find a 302 redirected and then your target URL in "Location:" header statement.