Python編程在flask中模擬進行Restful的CRUD操作

今天小編就爲大家分享一篇關於Python編程在flask中模擬進行Restful的CRUD操作,小編覺得內容挺不錯的,現在分享給大家,具有很好的參考價值,需要的朋友一起跟隨小編來看看吧

這篇文章中我們將通過對HelloWorld的message進行操作,介紹一下如何使用flask進行Restful的CRUD。

概要信息

事前準備: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$

代碼示例:HTTP謂詞(GET)

就像angular的插值表達式在模版中的作用一樣,在flask中也可以一樣使用,如果不熟悉angular的插值表達式的話也不要緊,看完下面的例子,基本上就會有一個大致的印象。

代碼示例

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$

代碼解析:app.route中指定了HTTP謂詞GET,缺省GET可以省略,如果一個方法對應多個謂詞動作,通過request.method來分離時,可以寫成methods=[‘GET','POST']的形式

執行&確認

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

頁面確認

代碼示例:HTTP謂詞(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$

執行&結果確認

執行日誌

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

結果確認: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$

可以看到執行一次DELETE之後,兩條消息現在只剩下一條消息了,接下來使用POST添加再添加一條

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$

再執行一次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$

小結

這篇文章中,使用最簡單的方式在flask中模擬了一下如何進行Restful的CRUD操作,當然,實際的做法有很多種,在接下來的文章中還會介紹另外一種非常常見的輪子flask-restful.

總結

以上就是這篇文章的全部內容了,希望本文的內容對大家的學習或者工作具有一定的參考學習價值,謝謝大家對神馬文庫的支持。如果你想了解更多相關內容請查看下面相關鏈接

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