Flask中如何简便从Request中提取请求的参数值

柔光的暖阳◎ 2022-06-17 10:59 213阅读 0赞

引言： Flask是Python非常著名的微服务Web框架，但是其并未提供简便的从Request中提取参数的方式，本文将介绍一种简便的方式。

1.  Flask-Request-Params

来自第三方的Flask插件，方便从Request中提取相应的参数值。

2.  安装步骤

首先确认系统中已经按照了pip, 如果您还不知道什么pip的话，还请直接问问度娘即可。

>> pip install flask-request-params

[root@xxxx]# pip install flask-request-params
    Collecting flask-request-params
      Downloading http://mirrors.aliyun.com/pypi/packages/33/14/f41ab27df8d0c59ddfe5063a5bdfcb687174e7573eac62ded2f758b7447f/Flask-request-params-0.3.0.tar.gz
    Building wheels for collected packages: flask-request-params
      Running setup.py bdist_wheel for flask-request-params ... done
      Stored in directory: /root/.cache/pip/wheels/f6/31/ef/c20696a93be9b3472ef70a5774cac5cfe3959dc7623f4f6a04
    Successfully built flask-request-params
    Installing collected packages: flask-request-params
    Successfully installed flask-request-params-0.3.0

检查一下pip是否安装成功：

>> pip show flask-request-params

[root@xxxx]# pip show flask-request-params
    Name: Flask-request-params
    Version: 0.3.0
    Summary: Flask-request-params provides Rails-like interface to HTTP Request Parameters for Flask.
    Home-page: https://github.com/bluele/flask-request-params
    Author: bluele
    Author-email: jksmphone@gmail.com
    License: MIT
    Location: /opt/python36env/lib/python3.6/site-packages
    Requires:

3.  如何使用？

客户端代码：

$ curl -X POST http://localhost:5000/echo/user -d 'user[name]=john&user[password]=pass'
    {
      "path": "user",
      "user": {
        "name": "john",
        "password": "pass"
      }
    }
    
    # support array type
    $ curl -X POST http://localhost:5000/echo/lang -d 'languages[]=python&languages[]=golang'
    {
      "path": "lang",
      "languages": [
        "python",
        "golang"
      ]
    }
    
    # support strong_parameters
    $ curl -X POST http://localhost:5000/user -d 'user[name]=bluele&user[password]=password'
    {
      "name": "bluele",
      "password": "password"
    }

服务端代码：

from flask import Flask, request, render_template, jsonify
    from flask_request_params import bind_request_params
    
    
    app = Flask(__name__)
    app.secret_key = 'secret'
    # bind rails like params to request.params
    app.before_request(bind_request_params)
    
    # just return request.params
    @app.route('/echo/<path>', methods=['GET', 'POST'])
    def echo(path):
        return jsonify(request.params)
    
    @app.route('/user', methods=['POST'])
    def create_user():
        user = request.params.require('user').permit('name', 'password')
        # do something
        return jsonify(user)
    
    # serve at localhost:5000
    app.run(debug=True)

核心的代码方法是：  request.params.require('xx").permit(),以及， request.params方法

url地址中的参数，以参数的形式传递进入处理函数体之内。

4.  如何获取GET请求中的params?

from flask import request
    
    @app.route('/data')
    def data():
        # here we want to get the value of user (i.e. ?user=some-value)
        user = request.args.get('user')
        param_str = request.query_string

5.  总结

这里列举了三种方式方法来获取Http Request中的参数处理过程，综合来说，还是非常简单易用的。