Python中requests返回200但r.json()报JSONDecodeError求助

问题说明 #

使用Python的requests库发送POST请求时，得到了Response [200]响应，但调用r.json()方法时触发JSONDecodeError。Chrome开发者工具的Payload标签下存在其他键，已尝试传入animal_ids等参数，目标是获取返回JSON中animals/icons下的comment和title字段。

代码示例 #

def icons():
    data = {"key": api_key, "cookie": cookie, 
            "start_date": date1.strftime('20%y-%m-%dT00:00:00-07:00'), 
            "end_date": date2.strftime('20%y-%m-%dT00:00:00-07:00'), 
            "animal_ids": animal_ids
            }
    r = requests.post(url, data=data)
    return r.json()
print(icons())

报错信息 #

Traceback (most recent call last):
  File "C:\Users\geiss\AppData\Local\Programs\Python\Python311\Lib\site-packages\requests\models.py", line 971, in json
    return complexjson.loads(self.text, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\geiss\AppData\Local\Programs\Python\Python311\Lib\json\__init__.py", line 346, in loads
    return _default_decoder.decode(s)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\geiss\AppData\Local\Programs\Python\Python311\Lib\json\decoder.py", line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\geiss\AppData\Local\Programs\Python\Python311\Lib\json\decoder.py", line 355, in raw_decode
    raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\geiss\postreq.py", line 17, in <module>
    print(icons())
          ^^^^^^^
  File "C:\Users\geiss\postreq.py", line 16, in icons
    return r.json()
           ^^^^^^^^
  File "C:\Users\geiss\AppData\Local\Programs\Python\Python311\Lib\site-packages\requests\models.py", line 975, in json
    raise RequestsJSONDecodeError(e.msg, e.doc, e.pos)
requests.exceptions.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

期望返回的JSON数据 #

{
    "success": true,
    "error": false,
    "data": {
        "animals": {
            "9488": {
                "icons": [
                    {
                        "id": null,
                        "animal_id": "9488",
                        "color_label_template_id": "27",
                        "comment": "Can open gates 12/8/21",
                        "created_at": "1638992225",
                        "created_by": "120",
                        "edited_at": null,
                        "edited_by": null,
                        "is_deleted": "0",
                        "deleted_at": null,
                        "deleted_by": null,
                        "fontawesome_icon_id": "1495",
                        "color_label_template_group_id": null,
                        "title": "Opens Gates",
                        "color": "#ff792f",
                        "capacity": null,
                        "checkout_alert": "0",
                        "checkin_alert": "1",
                        "reservation_creation_alert": "0",
                        "owner_details_alert": "0",
                        "animal_details_alert": "0",
                        "reservation_details_alert": "0",
                        "class": "fa fa-surprise",
                        "is_pro": "0",
                        "name": null,
                        "location_id": null,
                        "animal_color_label_id": "8341",
                        "type": "custom"
                    },
                    {
                        "id": null,
                        "animal_id": "9488",
                        "color_label_template_id": "38",
                        "comment": "see employee notes",
                        "created_at": "1639781526",
                        "created_by": "137",
                        "edited_at": null,
                        "edited_by": null,
                        "is_deleted": "0",
                        "deleted_at": null,
                        "deleted_by": null,
                        "fontawesome_icon_id": "173",
                        "color_label_template_group_id": null,
                        "title": "Grooming",
                        "color": "#16537e",
                        "capacity": null,
                        "checkout_alert": "0",
                        "checkin_alert": "1",
                        "reservation_creation_alert": "1",
                        "owner_details_alert": "0",
                        "animal_details_alert": "1",
                        "reservation_details_alert": "1",
                        "class": "fa fa-scissors",
                        "is_pro": "0",
                        "name": null,
                        "location_id": null,
                        "animal_color_label_id": "8461",
                        "type": "custom"
                    }
                ]
            }
        }
    }
}

解决步骤 #

• 排查响应内容：200状态码仅表示请求成功，不代表返回的是JSON。在调用r.json()前添加print(r.text)，查看实际返回的内容，可能是空字符串、HTML页面或其他非JSON格式。
• 核对请求格式：打开Chrome开发者工具查看Payload提交类型：
  • 如果是application/json格式，将requests.post(url, data=data)改为requests.post(url, json=data)，requests会自动设置正确的Content-Type请求头。
  • 如果是表单格式（application/x-www-form-urlencoded），确认所有Payload中的键都已包含在data字典中，没有遗漏。
• 检查参数格式：确认animal_ids的类型是否符合后端要求（字符串/列表），日期格式是否和浏览器提交的完全一致。
• 添加必要请求头：复制Chrome中请求的User-Agent、Referer等头信息，添加到请求中：

  headers = {
      "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36"
  }
  r = requests.post(url, data=data, headers=headers)
  

• 添加异常处理：捕获JSONDecodeError时输出响应内容，方便定位问题：

  try:
      return r.json()
  except requests.exceptions.JSONDecodeError:
      print("非JSON响应内容：", r.text)
      return None
  

• 提取目标字段：成功获取JSON后，按层级遍历提取comment和title：

  result = icons()
  if result and result.get("success"):
      for animal_data in result["data"]["animals"].values():
          for icon in animal_data["icons"]:
              print(f"标题：{icon['title']}，评论：{icon['comment']}")
  

内容的提问来源于stack exchange，提问作者SnazzyPete