Flask基本用法：一个HelloWorld，搭建服务、发起请求

?1、简介

Flask是一个轻量的web服务框架，我们可以利用它快速搭建一个服务，对外提供接口，其他人可以轻松调用我们的服务。这对算法工程师来说比较关键，我们通常不擅长搞开发，这种框架十分适合将算法封装成服务的形式提供给其他人使用。

更多介绍可从搜索引擎找到，这里不过多介绍。我们直接给出一个使用示例，相信大家看了后能快速掌握Flask的基本用法。

2、Flask使用示例

首先，编写一个server.py，作为服务：

from flask import Flask, request

app = Flask("Demo")


@app.route('/hello', methods=['POST', 'GET'])
def display():
    return {"message": "HelloFlask!", "status": 0}


@app.route('/send_snapshot', methods=['POST'])
def process_snapshot():
    # get post data
    data = request.get_json()
    print("got post data: {}".format(data))

    # process
    ...

    result = {
        "status": 0,
        "message": "send success!",
    }
    return result


if __name__ == '__main__':
    app.run(port=2023, host='127.0.0.1', debug=True)

然后，编写一个client.py，作为客户端，调用上面的服务进行测试：

import requests
import json


def demo_hello():
    url = "http://127.0.0.1:2023/hello"
    response = requests.post(url)

    if response.status_code == 200:
        response_data = json.loads(response.content)
        print("got response: {}".format(response_data))
    else:
        print("failed!")


def demo_send():
    url = "http://127.0.0.1:2023/send_snapshot"

    data = {
        "start_timestamp": 1,
        "end_timestamp": 2,
        "img": None
    }
    response = requests.post(url, json=data)

    if response.status_code == 200:
        response_data = json.loads(response.content)
        print("send over, got response: {}".format(response_data))
    else:
        print("send failed!")


if __name__ == '__main__':
    demo_hello()
    demo_send()

先启动server，再运行client，即可得到如下结果：

1. 运行server
python server.py
结果形如：
 * Serving Flask app 'Demo'
 * Debug mode: on
WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.
 * Running on http://127.0.0.1:2023
Press CTRL+C to quit
 * Restarting with stat
 * Debugger is active!
 * Debugger PIN: 887-814-515


2. 运行client.py
python client.py
结果形如：
got response: {'message': 'HelloFlask!', 'status': 0}
send over, got response: {'message': 'send success!', 'status': 0}

参考

官方文档：Welcome to Flask — Flask Documentation (3.0.x)

github：GitHub - pallets/flask: The Python micro framework for building web applications.?