python编程基础:快速微服务框架指南:flask:4: Restful的CRUD - Go语言中文社区

python编程基础:快速微服务框架指南:flask:4: Restful的CRUD


这里写图片描述
这篇文章中我们将通过对HelloWorld的message进行操作,介绍一下如何使用flask进行Restful的CRUD。

概要信息

项目 说明
官方网站 https://www.palletsprojects.com/p/flask/
开源/闭源 开源
License类别 BSD License
代码管理地址 https://github.com/pallets/flask
开发语言 Python
支持平台 鉴于python的跨平台特性,可运行于等多种操作系统
当前版本 1.0.2 (2018/05/02)

事前准备:flask

liumiaocn:flask liumiao$ which flask
/usr/local/bin/flask
liumiaocn:flask liumiao$ flask --version
Flask 1.0.2
Python 2.7.10 (default, Jul 15 2017, 17:16:57) 
[GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.31)]
liumiaocn:flask liumiao$ 

代码示例:HTTP谓词(GET)

就像angular的插值表达式在模版中的作用一样,在flask中也可以一样使用,如果不熟悉angular的插值表达式的话也不要紧,看完下面的例子,基本上就会有一个大致的印象。

代码示例

liumiaocn:flask liumiao$ cat flask_4.py 
#!/usr/bin/python

from flask import Flask
from flask import render_template

app = Flask(__name__)

greeting_messages=["Hello World", "Hello Python"]

@app.route("/api/messages",methods=['GET'])
def get_messages():
    return render_template("resttest.html",messages=greeting_messages) 

if __name__ == "__main__":
    app.debug=True
    app.run(host='0.0.0.0',port=7000)
liumiaocn:flask liumiao$

模版文件

liumiaocn:flask liumiao$ cat templates/resttest.html 
<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8">
  <title>Hello Restful</title>
</head>

<body>
        {% for message in messages %}
  <h1>{{ message }}</h1>
        {% endfor %}
</body>

</html>
liumiaocn:flask liumiao$

代码解析:app.route中指定了HTTP谓词GET,缺省GET可以省略,如果一个方法对应多个谓词动作,通过request.method来分离时,可以写成methods=[‘GET’,’POST’]的形式

执行&确认

liumiaocn:flask liumiao$ ./flask_4.py 
 * Serving Flask app "flask_4" (lazy loading)
 * Environment: production
   WARNING: Do not use the development server in a production environment.
   Use a production WSGI server instead.
 * Debug mode: on
 * Running on http://0.0.0.0:7000/ (Press CTRL+C to quit)
 * Restarting with stat
 * Debugger is active!
 * Debugger PIN: 131-533-062

页面确认
这里写图片描述

代码示例:HTTP谓词(DELETE|PUT|POST)

liumiaocn:flask liumiao$ cat flask_4.py 
#!/usr/bin/python

from flask import Flask
from flask import render_template
from flask import request
import json

app = Flask(__name__)

greeting_messages=["Hello World", "Hello Python"]

#HTTP: GET: Retrieve operation
@app.route("/api/messages",methods=['GET'])
def get_messages():
    return render_template("resttest.html",messages=greeting_messages) 

#HTTP: DELETE: Delete operation
@app.route("/api/messages/<messageid>",methods=['DELETE'])
def delete_message(messageid):
    global greeting_messages
    del greeting_messages[int(messageid)]
    return render_template("resttest.html",messages=greeting_messages) 

#HTTP: PUT:  Update operation
#HTTP: POST: Create operation
@app.route("/api/messages/<messageid>",methods=['PUT','POST'])
def update_message(messageid):
    global greeting_message
    msg_info=json.loads(request.get_data(True,True,False))
    #msg_info=request.args.get('message_info')
    #msg_info=request.form.get('message_info','default value')
    #msg_info=request.values.get('message_info','hello...')
    greeting_messages.append("Hello " + msg_info["message_info"])
    return render_template("resttest.html",messages=greeting_messages) 

if __name__ == "__main__":
    app.debug=True
    app.run(host='0.0.0.0',port=7000)
liumiaocn:flask liumiao$

执行&结果确认

执行日志

liumiaocn:flask liumiao$ ./flask_4.py 
 * Serving Flask app "flask_4" (lazy loading)
 * Environment: production
   WARNING: Do not use the development server in a production environment.
   Use a production WSGI server instead.
 * Debug mode: on
 * Running on http://0.0.0.0:7000/ (Press CTRL+C to quit)
 * Restarting with stat
 * Debugger is active!
 * Debugger PIN: 131-533-062

结果确认:Delete

liumiaocn:flask liumiao$ curl -X DELETE http://localhost:7000/api/messages/1
<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8">
    <title>Hello Restful</title>
</head>

<body>

    <h1>Hello World</h1>

</body>

</html>liumiaocn:flask liumiao$

可以看到执行一次DELETE之后,两条消息现在只剩下一条消息了,接下来使用POST添加再添加一条

liumiaocn:flask liumiao$ curl -X POST -d '{"message_info":"LiuMiaoPost"}' http://localhost:7000/api/messages/3
<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8">
    <title>Hello Restful</title>
</head>

<body>

    <h1>Hello World</h1>

    <h1>Hello LiuMiaoPost</h1>

</body>

</html>liumiaocn:flask liumiao$

再执行一次PUT操作

liumiaocn:flask liumiao$ curl -X PUT -d '{"message_info":"LiuMiaoPut"}' http://localhost:7000/api/messages/4
<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8">
    <title>Hello Restful</title>
</head>

<body>

    <h1>Hello World</h1>

    <h1>Hello LiuMiaoPost</h1>

    <h1>Hello LiuMiaoPut</h1>

</body>

</html>liumiaocn:flask liumiao$

总结

这篇文章中,使用最简单的方式在flask中模拟了一下如何进行Restful的CRUD操作,当然,实际的做法有很多种,在接下来的文章中还会介绍另外一种非常常见的轮子flask-restful.

版权声明:本文来源CSDN,感谢博主原创文章,遵循 CC 4.0 by-sa 版权协议,转载请附上原文出处链接和本声明。
原文链接:https://blog.csdn.net/liumiaocn/article/details/80728020
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  • 发表于 2019-08-27 00:13:46
  • 阅读 ( 2232 )
  • 分类:Go Web框架

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