Flask Web开发入门（十三）之构建REST API

港控/mmm° 2022-06-02 11:53 163阅读 0赞

关于REST API，我们先看一个比较形象的图：  
![这里写图片描述][SouthEast]

在我们之前的章节中，我们其实已经涉及到了Flask框架下REST API接口的构建，比如，文件下载接口：

# 文件下载
    @app.route('/download/<path:filename>')
    def send_html(filename):
        logger.debug("download file, path is %s" % filename)
        return send_from_directory(app.config['UPLOAD_PATH'], filename, as_attachment=True)

或者，图片显示接口

# show photo
    @app.route('/files/<string:filename>', methods=['GET'])
    def show_photo(filename):
        if request.method == 'GET':
            if filename is None:
                pass
            else:
                logger.debug('filename is %s' % filename)
                image_data = open(os.path.join(app.config['UPLOAD_PATH'], 'files/%s' % filename), "rb").read()
                response = make_response(image_data)
                response.headers['Content-Type'] = 'image/png'
                return response
        else:
            pass

或者这种格式：

@app.route('/detail/<int:id>',methods=['GET'])
    def detail(id):
        pass

除此之外，我们还可以使用**[Flask-RESTful][]**来构建REST API

> Flask-RESTful is an extension for Flask that adds support for quickly building REST APIs. It is a lightweight abstraction that works with your existing ORM/libraries. Flask-RESTful encourages best practices with minimal setup. If you are familiar with Flask, Flask-RESTful should be easy to pick up.

**[Flask-RESTful][]**可以很方便的将Python对象方法转换为RESTful API，下面我们示例说明：

定义类**MonitorApi**，类包含方法**get**，方法参数**id**：

# http://www.flaskapi.org/
    # https://www.fullstackpython.com/api-creation.html
    # 使用Flask-RESTful构建REST API
    # http://flask-restful.readthedocs.io/en/latest/
    # https://www.codementor.io/sagaragarwal94/building-a-basic-restful-api-in-python-58k02xsiq
    class MonitorApi(Resource):
        @staticmethod
        def get(id):
            return jsonify({
       'id': id, 'value': random.random(), 'timestamp': int(time.time())})

将方法注册为RESTful API：

api = Api(app)
    
    api.add_resource(monitor_api.MonitorApi, '/api/<id>')

接口测试如下：

![这里写图片描述][SouthEast 1]

[SouthEast]: /images/20220602/0803f9e58e0e4cce882096949fbf4d0d.png
[Flask-RESTful]: http://flask-restful.readthedocs.io/en/latest/
[SouthEast 1]: /images/20220602/87858931f6294093ad16d64279343f90.png