Postman请求正常但Python代码返回403错误的解决办法

问题描述 #

我编写了一段用http.client调用Williams-Sonoma API的Python代码：

import http.client

conn = http.client.HTTPSConnection("www.williams-sonoma.com")
payload = ''
headers = {
'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36',
'Cookie': '<some value here>'}

conn.request("GET", "/api/catalog/v1/catalogobjects/query/?skuId=8739781", payload, headers)
res = conn.getresponse()
data = res.read()
print(data.decode("utf-8"))

在Postman中发送完全相同的请求能获取正常的商品JSON响应：

[{"id":"glass-prep-bowl-8-piece-set","imageUrl":"https://assets.wsimgs.com/wsimgs/rk/images/dp/wcm/202340/0374/img40t.jpg","name":"Glass Prep Mixing Bowls, Set of 8","salePriceMax":34.95,"salePriceMin":34.95,"regularPriceMax":24.95,"regularPriceMin":24.95,"skuId":"8739781","available":true,"sellable":true}]

但Python代码执行后返回403 Restricted Access错误页面：

<!DOCTYPE html>
<html>
<head>
    <title>Williams-Sonoma: 403 - Restricted Access</title>
    <meta charset="utf-8" />
    <link rel="stylesheet" href="/netstorage/css/common.css" type="text/css" media="all" />
    <link rel="stylesheet" href="/netstorage/css/errors.css" type="text/css" media="all" />
</head>

<body>
    <div class="error-container">
        <img src="/netstorage/images/logo-ws.png" alt="Williams-Sonoma" />
        <p>Sorry, due to website restrictions we are unable to display the requested page.</p>
    </div>

<!-- Analytics -->
    <script type="text/javascript">
      window.digitalData = {
        page: {
          pageName: "Restricted Access Error",
          attributes: {
            cmPageId : "Restricted Access Error",
            cmCategoryId : "ERROR"
          },
          pageCategory: {
            primaryCategory: "error"
          }
        }
      };
      var utag_data = {};
      (function(a,b,c,d){
          a='//tags.tiqcdn.com/utag/wsi/williamssonoma/prod/utag.js';
          b=document;c='script';d=b.createElement(c);
          d.src=a;
          d.type='text/java'+c;
          d.async=true;
          a=b.getElementsByTagName(c)[0];
          a.parentNode.insertBefore(d,a);
      })();
    </script>
<!-- end Analytics -->
</body>
</html>

问题原因 #

服务器返回403通常是因为请求缺少必要的验证信息：Postman会自动添加浏览器默认的请求头，而你的Python代码只指定了User-Agent和Cookie，缺少Accept、Referer等关键头信息；另外Cookie值可能不完整或无效。

解决办法 #

1. 完整复制Postman的请求头 #

将Postman中请求的所有头信息复制到Python代码中，确保请求头和Postman完全一致。修改后的http.client代码如下：

import http.client

conn = http.client.HTTPSConnection("www.williams-sonoma.com")
payload = ''
headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36',
    'Cookie': '替换为Postman中完整的Cookie值',
    'Accept': 'application/json, text/plain, */*',
    'Accept-Language': 'en-US,en;q=0.9',
    'Accept-Encoding': 'gzip, deflate, br',
    'Referer': 'https://www.williams-sonoma.com/',
    'Connection': 'keep-alive'
}

conn.request("GET", "/api/catalog/v1/catalogobjects/query/?skuId=8739781", payload, headers)
res = conn.getresponse()
data = res.read()
print(data.decode("utf-8"))

2. 使用requests库简化请求（推荐） #

requests库更易用，能自动处理很多底层细节，模拟浏览器请求更准确。示例代码：

import requests

url = "https://www.williams-sonoma.com/api/catalog/v1/catalogobjects/query/?skuId=8739781"

headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36',
    'Cookie': '替换为Postman中完整的Cookie值',
    'Accept': 'application/json, text/plain, */*',
    'Accept-Language': 'en-US,en;q=0.9',
    'Accept-Encoding': 'gzip, deflate, br',
    'Referer': 'https://www.williams-sonoma.com/',
    'Connection': 'keep-alive'
}

response = requests.get(url, headers=headers)
print(response.json())

注意事项 #

• 确保Cookie值是从Postman的请求头中完整复制的，不要遗漏任何键值对，Cookie中的会话标识或CSRF令牌是服务器验证的关键。
• 如果后续再次出现403，可能是Cookie过期，需要重新从Postman中获取最新的Cookie值。

内容的提问来源于stack exchange，提问作者Ashish Khatana