Python Requests报'Remote end closed connection without response'问题求助

在VirtualBox的Ubuntu 22.04.2 LTS（Windows 10主机）上编写脚本，需通过POST请求上传JSON文件和传感器名称字符串至指定接口，使用requests库时出现错误：Remote end closed connection without response。但通过curl发送请求、Python发送GET请求均正常，尝试添加User-Agent请求头也未解决问题。

相关代码 #

headers = {
        'accept': '*/*',
        'Content-Type': 'multipart/form-data',
}

files = {
        'data': (None, './dati_1.json'),
        'sensor_name': (None, 'SENSOR_NAME'),
}
response = requests.post('http://IP_ADDRESS/sensors/store', headers=headers, files=files)
print(response)

报错信息 #

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 699, in urlopen
    httplib_response = self._make_request(
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 445, in _make_request
    six.raise_from(e, None)
  File "<string>", line 3, in raise_from
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 440, in _make_request
    httplib_response = conn.getresponse()
  File "/usr/lib/python3.10/http/client.py", line 1374, in getresponse
    response.begin()
  File "/usr/lib/python3.10/http/client.py", line 318, in begin
    version, status, reason = self._read_status()
  File "/usr/lib/python3.10/http/client.py", line 287, in _read_status
    raise RemoteDisconnected("Remote end closed connection without"
http.client.RemoteDisconnected: Remote end closed connection without response

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/requests/adapters.py", line 439, in send
    resp = conn.urlopen(
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 755, in urlopen
    retries = retries.increment(
  File "/usr/lib/python3/dist-packages/urllib3/util/retry.py", line 532, in increment
    raise six.reraise(type(error), error, _stacktrace)
  File "/usr/lib/python3/dist-packages/six.py", line 718, in reraise
    raise value.with_traceback(tb)
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 699, in urlopen
    httplib_response = self._make_request(
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 445, in _make_request
    six.raise_from(e, None)
  File "<string>", line 3, in raise_from
  File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 440, in _make_request
    httplib_response = conn.getresponse()
  File "/usr/lib/python3.10/http/client.py", line 1374, in getresponse
    response.begin()
  File "/usr/lib/python3.10/http/client.py", line 318, in begin
    version, status, reason = self._read_status()
  File "/usr/lib/python3.10/http/client.py", line 287, in _read_status
    raise RemoteDisconnected("Remote end closed connection without"
urllib3.exceptions.ProtocolError: ('Connection aborted.', RemoteDisconnected('Remote end closed connection without response'))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/azzurra/tesi/prova1.py", line 39, in <module>
    response = requests.post('http://131.114.51.60:3100/sensors/store', headers=headers, files=files)
  File "/usr/lib/python3/dist-packages/requests/api.py", line 119, in post
    return request('post', url, data=data, json=json, **kwargs)
  File "/usr/lib/python3/dist-packages/requests/api.py", line 61, in request
    return session.request(method=method, url=url, **kwargs)
  File "/usr/lib/python3/dist-packages/requests/sessions.py", line 542, in request
    resp = self.send(prep, **send_kwargs)
  File "/usr/lib/python3/dist-packages/requests/sessions.py", line 655, in send
    r = adapter.send(request, **kwargs)
  File "/usr/lib/python3/dist-packages/requests/adapters.py", line 498, in send
    raise ConnectionError(err, request=request)
requests.exceptions.ConnectionError: ('Connection aborted.', RemoteDisconnected('Remote end closed connection without response'))

问题出在两个地方：

1. 手动指定了Content-Type: multipart/form-data请求头，但requests处理files参数时会自动生成包含boundary分隔符的正确multipart请求头，手动指定会覆盖这个自动生成的头，导致服务端无法解析请求，直接断开连接。
2. 你没有实际读取JSON文件内容，只是传递了文件名字符串，服务端无法获取到文件数据。

修改后的代码：

import requests

headers = {
    'accept': '*/*',
    # 移除手动设置的Content-Type，让requests自动生成
}

# 读取JSON文件的二进制内容
with open('./dati_1.json', 'rb') as json_file:
    file_content = json_file.read()

files = {
    # 指定文件名、文件内容和正确的MIME类型
    'data': ('dati_1.json', file_content, 'application/json'),
    'sensor_name': (None, 'SENSOR_NAME'),
}

response = requests.post('http://IP_ADDRESS/sensors/store', headers=headers, files=files)
print(response.status_code)
print(response.text)

额外优化建议：

• 如果传感器名称只是普通表单字段，可单独用data参数传递，无需放到files里：

data = {'sensor_name': 'SENSOR_NAME'}
files = {'data': ('dati_1.json', file_content, 'application/json')}
response = requests.post('http://IP_ADDRESS/sensors/store', headers=headers, data=data, files=files)

• 开启调试日志对比请求差异：

import logging
import http.client

http.client.HTTPConnection.debuglevel = 1
logging.basicConfig()
logging.getLogger().setLevel(logging.DEBUG)
requests_log = logging.getLogger("requests.packages.urllib3")
requests_log.setLevel(logging.DEBUG)
requests_log.propagate = True

内容的提问来源于stack exchange，提问作者Kaz