位置字段不存在于后响应标题中

Question

我正在尝试使用Python请求库登录到网页。我将邮政请求发送到链接并收回响应，但是我缺少响应标题中的"位置"项目。我正在使用以下代码：

import requests
from bs4 import BeautifulSoup
url = 'https://aab.powerapp.nl/login'
headers = {'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.100 Safari/537.36'}
response = requests.get(url, headers=headers)
soup = BeautifulSoup(response.content)
token = soup.find('input', {'name': '_token'}).get('value')
headers['Cookie'] = '; '.join([x.name + '=' + x.value for x in response.cookies])
headers['Content-Type'] = 'application/x-www-form-urlencoded'
payload = {
        '_token': token,
        'emailaddress': '', 
        'password': ''
}
response = requests.post(url + '/validate', files=payload, headers=headers)

Chrome中所示的请求标题如下：

POST /login/validate HTTP/1.1
Host: aab.powerapp.nl
Connection: keep-alive
Content-Length: 90
Cache-Control: max-age=0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3
Origin: https://aab.powerapp.nl
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.100 Safari/537.36
Content-Type: application/x-www-form-urlencoded
Referer: https://aab.powerapp.nl/login
Accept-Encoding: gzip, deflate, br
Accept-Language: nl-NL,nl;q=0.9,en-US;q=0.8,en;q=0.7
Cookie: XSRF-TOKEN=eyJpdiI6InkyK1pWbzRcL3dmbVRPeVwvNW52UjFyUT09IiwidmFsdWUiOiJWazZXRGFDb0tWcGQ1WjhleHdSRzZYU202WXN3bG4wbG9YQnZZcUNYTndDcXJETDl2MGIrY0dnUVlOcUhoTmZKIiwibWFjIjoiZmNmNzlmMjc5YWRiMmMyNjk0MmI1YjE5ZTE2OTNmZGU5YTRlNDA0MDg3ZGE4NTI1ZTc3NTBkZjg0MjFjOTQzNSJ9; pa_session_aabp=eyJpdiI6IjlidWIxdlVybFl0UjJHOXorcnFmT2c9PSIsInZhbHVlIjoiM0JZXC9NNHJOWlFIVjBhQ2xxelN2ZENrSVBuTkpibzJybUhkSHRUeGpSTTRITnFyK2E1M3ExM2VjWjNnNG4rbXMiLCJtYWMiOiJmN2NjZGRkNjc2YTJkZjBjNGVkZDczODNlZDI1YTk5YTllODk1YmFiMDc4Mzc5MWM2ZDZmMThiZjNmMzU0MmU5In0%3D

我只收到以下标题：

{'Date': 'Sat, 29 Jun 2019 15:40:15 GMT', 'Server': 'Apache', 'Cache-Control': 'no-cache, private', 'Set-Cookie': 'pa_session_aabp=eyJpdiI6ImFwS21QNVpMRGh1ZHJ0ZW1vbCtia1E9PSIsInZhbHVlIjoiRHZHa1wvZlNKMnkzZVEzTCthQVZ1eGdjSmRVbEZVSVJ2RHN5ZXZwNEV6NmRkZVZnTVhTMVlGUWxES1dYUmdvQlgiLCJtYWMiOiIyNWRhYTRkNzUyZTdiYmI4ODYwMDBkMmVjMDRmNzliYzZmZDAzNzg4N2NiMTdkMWI3Y2YyZjQyOGI0MDFiZWJlIn0%3D; path=/; domain=aab.powerapp.nl; secure; httponly', 'Location': 'https://aab.powerapp.nl/login', 'Keep-Alive': 'timeout=5, max=100', 'Connection': 'Keep-Alive', 'Transfer-Encoding': 'chunked', 'Content-Type': 'text/html; charset=UTF-8', 'Content-Language': 'nl'}

我尝试将允许_redirect参数设置为True和False，但我仍然无法将Location项目放回响应标头中。旁边，我尝试设置几个不同的请求标题，包括Cookie，Referer和User-Agent。除了在请求中以形式数据发送的emailaddress和password，也发送了第三个字段_token。我不确定这是否可能是问题的原因，因为我也不确定如何确定令牌的价值。

编辑：我发现作为表单数据发送的令牌可以从登录页面的HTML提取。我已经对脚本进行了一些更改，以反映这一知识。不幸的是，这似乎没有解决我的问题。

Answer 1

我通过使用请求session与使用数据参数而不是文件参数的请求进行修复。代码如下：

import requests
from bs4 import BeautifulSoup
session = requests.session()
url = 'https://aab.powerapp.nl/login'
headers = {'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.100 Safari/537.36',
           "Upgrade-Insecure-Requests": "1"}
response = session.get(url, headers=headers)
soup = BeautifulSoup(response.content)
token = soup.find('input', {'name': '_token'}).get('value')
headers['Content-Type'] = 'application/x-www-form-urlencoded'
payload = {
        '_token': token,
        'emailaddress': '', 
        'password': ''
}
response = session.post(url + '/validate', data=payload, headers=headers, allow_redirects=False)

Answer 2

您应该在每次会话中，一开始就发送一次凭据，并且在成功通过该过程后，您将获得该令牌字符串，该字符串有效，该字符串在服务器端定义了一段时间。授权后需要对API的任何其他呼叫，以将令牌发送为标题。