Python 如何在烧瓶中设置响应标题？_Python_Flask

Python 如何在烧瓶中设置响应标题？

python flask

Python 如何在烧瓶中设置响应标题？,python,flask,Python,Flask,这是我的代码： @app.route('/hello', methods=["POST"]) def hello(): resp = make_response() resp.headers['Access-Control-Allow-Origin'] = '*' return resp 但是，当我从浏览器向服务器发出请求时，会出现以下错误： XMLHttpRequest cannot load http://localhost:5000/hello. No 'Acc

这是我的代码：

@app.route('/hello', methods=["POST"])
def hello():
    resp = make_response()
    resp.headers['Access-Control-Allow-Origin'] = '*'
    return resp

但是，当我从浏览器向服务器发出请求时，会出现以下错误：

XMLHttpRequest cannot load http://localhost:5000/hello. 
No 'Access-Control-Allow-Origin' header is present on the requested resource.

我也尝试过这种方法，在请求之后设置响应头：

@app.after_request
def add_header(response):
    response.headers['Access-Control-Allow-Origin'] = '*'
    return response

没有骰子。我也犯了同样的错误。有没有办法只在route函数中设置响应头？像这样的东西很理想：

@app.route('/hello', methods=["POST"])
    def hello(response): # is this a thing??
        response.headers['Access-Control-Allow-Origin'] = '*'
        return response

但是我找不到任何方法来做这件事。请帮忙

编辑

如果我使用POST请求卷曲url，如下所示：

curl -iX POST http://localhost:5000/hello

我得到的答复是：

HTTP/1.0 500 INTERNAL SERVER ERROR
Content-Type: text/html
Content-Length: 291
Server: Werkzeug/0.9.6 Python/2.7.6
Date: Tue, 16 Sep 2014 03:58:42 GMT

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<title>500 Internal Server Error</title>
<h1>Internal Server Error</h1>
<p>The server encountered an internal error and was unable to complete your request.  Either the server is overloaded or there is an error in the application.</p>

HTTP/1.0 500内部服务器错误
内容类型：text/html
内容长度：291
服务器：Werkzeug/0.9.6 Python/2.7.6
日期：2014年9月16日星期二03:58:42 GMT
500内部服务器错误
内部服务器错误
服务器遇到内部错误，无法完成您的请求。服务器过载或应用程序中存在错误

有什么想法吗？

你可以很容易地做到：

@app.route("/")
def home():
    resp = flask.Response("Foo bar baz")
    resp.headers['Access-Control-Allow-Origin'] = '*'
    return resp

看和

但是我发现您还有一个问题，因为

after\u请求

也应该正确处理它

编辑
我刚刚注意到您已经在使用

make_response

，这是一种方法。就像我之前说的那样，

在请求之后

也应该起作用。尝试通过curl点击端点，看看标题是什么：

curl -i http://127.0.0.1:5000/your/endpoint

你应该看到

> curl -i 'http://127.0.0.1:5000/'
HTTP/1.0 200 OK
Content-Type: text/html; charset=utf-8
Content-Length: 11
Access-Control-Allow-Origin: *
Server: Werkzeug/0.8.3 Python/2.7.5
Date: Tue, 16 Sep 2014 03:47:13 GMT

注意访问控制允许原点标题

编辑2
正如我所怀疑的，你得到了500分，所以你没有像你想的那样设置标题。在启动应用程序之前，请尝试添加

app.debug=True

，然后重试。您应该得到一些输出，显示问题的根本原因

例如：

@app.route("/")
def home():
    resp = flask.Response("Foo bar baz")
    user.weapon = boomerang
    resp.headers['Access-Control-Allow-Origin'] = '*'
    return resp

给出了一个格式良好的html错误页面，在底部有这个页面（有助于curl命令）

这是我的工作

from flask import Flask
from flask import Response

app = Flask(__name__)

@app.route("/")
def home():
    return Response(headers={'Access-Control-Allow-Origin':'*'})

if __name__ == "__main__":
    app.run()

使用烧瓶的

make_response

，例如

@app.route("/")
def home():
    resp = make_response("hello") #here you could use make_response(render_template(...)) too
    resp.headers['Access-Control-Allow-Origin'] = '*'
    return resp

从

烧瓶。做出响应（*args）

有时有必要在视图中设置其他标题。由于视图不必返回响应对象，但可以返回一个由Flask本身转换为响应对象的值，因此向其添加标题变得很棘手。可以调用此函数而不是使用返回，您将得到一个响应对象，您可以使用它来附加标题

这就是如何在我的flask应用程序中添加标题的方法，它工作得非常好

@app.after_request
def add_header(response):
    response.headers['X-Content-Type-Options'] = 'nosniff'
    return response

我们可以使用Flask应用程序上下文，使用

Flask.g

使用

Flask.g

在Flask应用程序上下文中设置响应头的这种方法是线程安全的，可以用于从应用程序的任何文件设置自定义和动态属性，如果我们从任何帮助器类设置自定义/动态响应头，这将特别有用，也可以从任何其他文件访问（比如说像中间件等），这个

flask.g

是全局的，仅对该请求线程有效

假设我想从该应用程序调用的另一个api/http调用读取响应头，然后提取任何响应头并将其设置为该应用程序的响应头

示例代码：文件：helper.py

import flask
from flask import request, g
from multidict import CIMultiDict
from asyncio import TimeoutError as HttpTimeout
from aiohttp import ClientSession

    def _extract_response_header(response)
      """
      extracts response headers from response object 
      and stores that required response header in flask.g app context
      """
      headers = CIMultiDict(response.headers)
      if 'my_response_header' not in g:
        g.my_response_header= {}
        g.my_response_header['x-custom-header'] = headers['x-custom-header']


    async def call_post_api(post_body):
      """
      sample method to make post api call using aiohttp clientsession
      """
      try:
        async with ClientSession() as session:
          async with session.post(uri, headers=_headers, json=post_body) as response:
            responseResult = await response.read()
            _extract_headers(response, responseResult)
            response_text = await response.text()
      except (HttpTimeout, ConnectionError) as ex:
        raise HttpTimeout(exception_message)

import flask
from flask import request, g

class SimpleMiddleWare(object):
    """
    Simple WSGI middleware
    """

    def __init__(self, app):
        self.app = app
        self._header_name = "any_request_header"

    def __call__(self, environ, start_response):
        """
        middleware to capture request header from incoming http request
        """
        request_id_header = environ.get(self._header_name)
        environ[self._header_name] = request_id_header

        def new_start_response(status, response_headers, exc_info=None):
            """
            set custom response headers
            """
            # set the request header as response header
            response_headers.append((self._header_name, request_id_header))
            # this is trying to access flask.g values set in helper class & set that as response header
            values = g.get(my_response_header, {})
            if values.get('x-custom-header'):
                response_headers.append(('x-custom-header', values.get('x-custom-header')))
            return start_response(status, response_headers, exc_info)

        return self.app(environ, new_start_response)

from flask import Flask
import asyncio
from gevent.pywsgi import WSGIServer
from middleware import SimpleMiddleWare

app = Flask(__name__)
app.wsgi_app = SimpleMiddleWare(app.wsgi_app)

文件：

middleware.py

import flask
from flask import request, g
from multidict import CIMultiDict
from asyncio import TimeoutError as HttpTimeout
from aiohttp import ClientSession

    def _extract_response_header(response)
      """
      extracts response headers from response object 
      and stores that required response header in flask.g app context
      """
      headers = CIMultiDict(response.headers)
      if 'my_response_header' not in g:
        g.my_response_header= {}
        g.my_response_header['x-custom-header'] = headers['x-custom-header']


    async def call_post_api(post_body):
      """
      sample method to make post api call using aiohttp clientsession
      """
      try:
        async with ClientSession() as session:
          async with session.post(uri, headers=_headers, json=post_body) as response:
            responseResult = await response.read()
            _extract_headers(response, responseResult)
            response_text = await response.text()
      except (HttpTimeout, ConnectionError) as ex:
        raise HttpTimeout(exception_message)

import flask
from flask import request, g

class SimpleMiddleWare(object):
    """
    Simple WSGI middleware
    """

    def __init__(self, app):
        self.app = app
        self._header_name = "any_request_header"

    def __call__(self, environ, start_response):
        """
        middleware to capture request header from incoming http request
        """
        request_id_header = environ.get(self._header_name)
        environ[self._header_name] = request_id_header

        def new_start_response(status, response_headers, exc_info=None):
            """
            set custom response headers
            """
            # set the request header as response header
            response_headers.append((self._header_name, request_id_header))
            # this is trying to access flask.g values set in helper class & set that as response header
            values = g.get(my_response_header, {})
            if values.get('x-custom-header'):
                response_headers.append(('x-custom-header', values.get('x-custom-header')))
            return start_response(status, response_headers, exc_info)

        return self.app(environ, new_start_response)

from flask import Flask
import asyncio
from gevent.pywsgi import WSGIServer
from middleware import SimpleMiddleWare

app = Flask(__name__)
app.wsgi_app = SimpleMiddleWare(app.wsgi_app)

从主类调用中间件

文件：

main.py

import flask
from flask import request, g
from multidict import CIMultiDict
from asyncio import TimeoutError as HttpTimeout
from aiohttp import ClientSession

    def _extract_response_header(response)
      """
      extracts response headers from response object 
      and stores that required response header in flask.g app context
      """
      headers = CIMultiDict(response.headers)
      if 'my_response_header' not in g:
        g.my_response_header= {}
        g.my_response_header['x-custom-header'] = headers['x-custom-header']


    async def call_post_api(post_body):
      """
      sample method to make post api call using aiohttp clientsession
      """
      try:
        async with ClientSession() as session:
          async with session.post(uri, headers=_headers, json=post_body) as response:
            responseResult = await response.read()
            _extract_headers(response, responseResult)
            response_text = await response.text()
      except (HttpTimeout, ConnectionError) as ex:
        raise HttpTimeout(exception_message)

import flask
from flask import request, g

class SimpleMiddleWare(object):
    """
    Simple WSGI middleware
    """

    def __init__(self, app):
        self.app = app
        self._header_name = "any_request_header"

    def __call__(self, environ, start_response):
        """
        middleware to capture request header from incoming http request
        """
        request_id_header = environ.get(self._header_name)
        environ[self._header_name] = request_id_header

        def new_start_response(status, response_headers, exc_info=None):
            """
            set custom response headers
            """
            # set the request header as response header
            response_headers.append((self._header_name, request_id_header))
            # this is trying to access flask.g values set in helper class & set that as response header
            values = g.get(my_response_header, {})
            if values.get('x-custom-header'):
                response_headers.append(('x-custom-header', values.get('x-custom-header')))
            return start_response(status, response_headers, exc_info)

        return self.app(environ, new_start_response)

from flask import Flask
import asyncio
from gevent.pywsgi import WSGIServer
from middleware import SimpleMiddleWare

app = Flask(__name__)
app.wsgi_app = SimpleMiddleWare(app.wsgi_app)

您可以在args中发送请求：还有表示法

返回响应（headers={'Access-Control-Allow-Origin'：'*'）

，这对我来说更干净。我建议使用中间件来解决这个问题，或者只使用flask cors扩展