python視頻教程欄目為大家介紹Python Flask解決跨域問題。

系列文章目錄

Table of Contents

• 系列文章目錄
• 前言
• 使用步驟
  • 1. 引入庫
  • 2. 配置
    • 1. 使用 CORS函數 配置全局路由
    • 2. 使用 @cross_origin 來配置單行路由
  • 配置參數說明
• 總結
• 參考

前言

我靠，又跨域了

使用步驟

1. 引入庫

pip install flask-cors復制代碼

2. 配置

flask-cors 有兩種用法，一種為全局使用，一種對指定的路由使用

1. 使用 CORS函數 配置全局路由

from flask import Flask, requestfrom flask_cors import CORS  app = Flask(__name__) CORS(app, supports_credentials=True)復制代碼

其中 CORS 提供了一些參數幫助我們定制一下操作。

常用的我們可以配置 origins、methods、allow_headers、supports_credentials

所有的配置項如下：

:param resources:     The series of regular expression and (optionally) associated CORS     options to be applied to the given resource path.      If the argument is a dictionary, it's keys must be regular expressions,     and the values must be a dictionary of kwargs, identical to the kwargs     of this function.      If the argument is a list, it is expected to be a list of regular     expressions, for which the app-wide configured options are applied.      If the argument is a string, it is expected to be a regular expression     for which the app-wide configured options are applied.      Default : Match all and apply app-level configuration  :type resources: dict, iterable or string  :param origins:     The origin, or list of origins to allow requests from.     The origin(s) may be regular expressions, case-sensitive strings,     or else an asterisk      Default : '*' :type origins: list, string or regex  :param methods:     The method or list of methods which the allowed origins are allowed to     access for non-simple requests.      Default : [GET, HEAD, POST, OPTIONS, PUT, PATCH, DELETE] :type methods: list or string  :param expose_headers:     The header or list which are safe to expose to the API of a CORS API     specification.      Default : None :type expose_headers: list or string  :param allow_headers:     The header or list of header field names which can be used when this     resource is accessed by allowed origins. The header(s) may be regular     expressions, case-sensitive strings, or else an asterisk.      Default : '*', allow all headers :type allow_headers: list, string or regex  :param supports_credentials:     Allows users to make authenticated requests. If true, injects the     `Access-Control-Allow-Credentials` header in responses. This allows     cookies and credentials to be submitted across domains.      :note: This option cannot be used in conjuction with a '*' origin      Default : False :type supports_credentials: bool  :param max_age:     The maximum time for which this CORS request maybe cached. This value     is set as the `Access-Control-Max-Age` header.      Default : None :type max_age: timedelta, integer, string or None  :param send_wildcard: If True, and the origins parameter is `*`, a wildcard     `Access-Control-Allow-Origin` header is sent, rather than the     request's `Origin` header.      Default : False :type send_wildcard: bool  :param vary_header:     If True, the header Vary: Origin will be returned as per the W3     implementation guidelines.      Setting this header when the `Access-Control-Allow-Origin` is     dynamically generated (e.g. when there is more than one allowed     origin, and an Origin than '*' is returned) informs CDNs and other     caches that the CORS headers are dynamic, and cannot be cached.      If False, the Vary header will never be injected or altered.      Default : True :type vary_header: bool復制代碼

2. 使用 @cross_origin 來配置單行路由

from flask import Flask, requestfrom flask_cors import cross_origin  app = Flask(__name__)@app.route('/')@cross_origin(supports_credentials=True)def hello():     name = request.args.get("name", "World")    return f'Hello, {name}!'復制代碼

其中 cross_origin 和 CORS 提供一些基本相同的參數。

常用的我們可以配置 origins、methods、allow_headers、supports_credentials

所有的配置項如下：

:param origins:     The origin, or list of origins to allow requests from.     The origin(s) may be regular expressions, case-sensitive strings,     or else an asterisk      Default : '*' :type origins: list, string or regex  :param methods:     The method or list of methods which the allowed origins are allowed to     access for non-simple requests.      Default : [GET, HEAD, POST, OPTIONS, PUT, PATCH, DELETE] :type methods: list or string  :param expose_headers:     The header or list which are safe to expose to the API of a CORS API     specification.      Default : None :type expose_headers: list or string  :param allow_headers:     The header or list of header field names which can be used when this     resource is accessed by allowed origins. The header(s) may be regular     expressions, case-sensitive strings, or else an asterisk.      Default : '*', allow all headers :type allow_headers: list, string or regex  :param supports_credentials:     Allows users to make authenticated requests. If true, injects the     `Access-Control-Allow-Credentials` header in responses. This allows     cookies and credentials to be submitted across domains.      :note: This option cannot be used in conjuction with a '*' origin      Default : False :type supports_credentials: bool  :param max_age:     The maximum time for which this CORS request maybe cached. This value     is set as the `Access-Control-Max-Age` header.      Default : None :type max_age: timedelta, integer, string or None  :param send_wildcard: If True, and the origins parameter is `*`, a wildcard     `Access-Control-Allow-Origin` header is sent, rather than the     request's `Origin` header.      Default : False :type send_wildcard: bool  :param vary_header:     If True, the header Vary: Origin will be returned as per the W3     implementation guidelines.      Setting this header when the `Access-Control-Allow-Origin` is     dynamically generated (e.g. when there is more than one allowed     origin, and an Origin than '*' is returned) informs CDNs and other     caches that the CORS headers are dynamic, and cannot be cached.      If False, the Vary header will never be injected or altered.      Default : True :type vary_header: bool  :param automatic_options:     Only applies to the `cross_origin` decorator. If True, Flask-CORS will     override Flask's default OPTIONS handling to return CORS headers for     OPTIONS requests.      Default : True :type automatic_options: bool復制代碼

配置參數說明

總結

在 flask 的跨域配置中，我們可以使用 flask-cors 來進行配置，其中 CORS 函數 用來做全局的配置, @cross_origin 來實現特定路由的配置。