python实现Restful服务 (基于flask)(1)

参考：https://www.jianshu.com/p/6ac1cab17929

参考：https://www.cnblogs.com/alexyuyu/p/6243362.html

参考：http://docs.jinkan.org/docs/flask/quickstart.html.

安装基于REST的Web客户端

1、helloworld的运行

from flask import Flask
# Flask初始化参数尽量使用你的包名，这个初始化方式是官方推荐的，官方解释：http://flask.pocoo.org/docs/0.12/api/#flask.Flask
app = Flask(__name__)
@app.route('/HelloWorld')
def hello_world():
    return "Hello World!"
app.run()

2、使用get 方法获取资源

# -*- coding: utf-8 -*-
from flask import Flask, jsonify, abort, make_response
app = Flask(__name__)
articles = [
    {
        'id': 1,
        'title': 'the way to python',
        'content': 'tuple, list, dict'
    },
    {
        'id': 2,
        'title': 'the way to REST',
        'content': 'GET, POST, PUT'
    }
]
@app.route('/blog/api/articles', methods=['GET'])
def get_articles():
    return jsonify({'articles': articles})
@app.route('/blog/api/articles/<int:article_id>', methods=['GET'])
def get_article(article_id):
    article = filter(lambda a: a['id'] == article_id, articles)
    if len(article) == 0:
        abort(404)
    return jsonify({'article': article[0]})
@app.errorhandler(404)
def not_found(error):
    return make_response(jsonify({'error': 'Not found'}), 404)
if __name__ == '__main__':
    app.run(host='127.0.0.1', port=5632)

在终端输入如下得到结果：

$ curl -i http://localhost:5632/blog/api/articles
HTTP/1.0 200 OK
Content-Type: application/json
Content-Length: 225
Server: Werkzeug/0.12.2 Python/3.6.3
Date: Thu, 22 Mar 2018 15:36:17 GMT

{
  "articles": [
    {
      "content": "tuple, list, dict",
      "id": 1,
      "title": "the way to python"
    },
    {
      "content": "GET, POST, PUT",
      "id": 2,
      "title": "the way to REST"
    }
  ]
}

3、使用flask的RESTful扩展库

from flask import Flask
from flask_restful import reqparse, abort, Api, Resource
app = Flask(__name__)
api = Api(app)
TODOS = {
    'todo1': {'task': 'build an API'},
    'todo2': {'task': '哈哈哈'},
    'todo3': {'task': 'profit!'},
}
def abort_if_todo_doesnt_exist(todo_id):
    if todo_id not in TODOS:
        abort(404, message="Todo {} doesn't exist".format(todo_id))
parser = reqparse.RequestParser()
parser.add_argument('task')
# Todo
# shows a single todo item and lets you delete a todo item
class Todo(Resource):
    def get(self, todo_id):
        abort_if_todo_doesnt_exist(todo_id)
        return TODOS[todo_id]
    def delete(self, todo_id):
        abort_if_todo_doesnt_exist(todo_id)
        del TODOS[todo_id]
        return '', 204
    def put(self, todo_id):
        args = parser.parse_args()
        task = {'task': args['task']}
        TODOS[todo_id] = task
        return task, 201
# TodoList
# shows a list of all todos, and lets you POST to add new tasks
class TodoList(Resource):
    def get(self):
        return TODOS
    def post(self):
        args = parser.parse_args()
        todo_id = int(max(TODOS.keys()).lstrip('todo')) + 1
        todo_id = 'todo%i' % todo_id
        TODOS[todo_id] = {'task': args['task']}
        return TODOS[todo_id], 201
##
## Actually setup the Api resource routing here
##
api.add_resource(TodoList, '/todos')
api.add_resource(Todo, '/todos/<todo_id>')
if __name__ == '__main__':
    app.run()

查询列表结果：

查询单任务：

删除任务：

另一个例子：

from flask import Flask
from flask_restful import reqparse, abort, Api, Resource
app = Flask(__name__)
api = Api(app)
TODOS = {
    'todo1': {'task': 'build an API'},
    'todo2': {'task': '?????'},
    'todo3': {'task': 'profit!'},
}
def abort_if_todo_doesnt_exist(todo_id):
    if todo_id not in TODOS:
        abort(404, message="Todo {} doesn't exist".format(todo_id))
parser = reqparse.RequestParser()
parser.add_argument('task')
# Todo
# shows a single todo item and lets you delete a todo item
class Todo(Resource):
    def get(self, todo_id):
        abort_if_todo_doesnt_exist(todo_id)
        return TODOS[todo_id]
    def delete(self, todo_id):
        abort_if_todo_doesnt_exist(todo_id)
        del TODOS[todo_id]
        return '', 204
    def put(self, todo_id):
        args = parser.parse_args()
        task = {'task': args['task']}
        TODOS[todo_id] = task
        return task, 201
# TodoList
# shows a list of all todos, and lets you POST to add new tasks
class TodoList(Resource):
    def get(self):
        return TODOS
    def post(self):
        args = parser.parse_args()
        todo_id = int(max(TODOS.keys()).lstrip('todo')) + 1
        todo_id = 'todo%i' % todo_id
        TODOS[todo_id] = {'task': args['task']}
        return TODOS[todo_id], 201
##
## Actually setup the Api resource routing here
##
api.add_resource(TodoList, '/todos')
api.add_resource(Todo, '/todos/<todo_id>')
if __name__ == '__main__':
    app.run(debug=True)

通过终端进行如下相应任务：

获取列表：

$ curl http://localhost:5000/todos
{"todo1": {"task": "build an API"}, "todo2": {"task": "?????"}, "todo3": {"task": "profit!"}}

获取单个任务：

$ curl http://localhost:5000/todos/todo3
{"task": "profit!"}

删除一个任务：

curl http://localhost:5000/todos/todo2 -X DELETE -v

增加一个任务：

$ curl http://localhost:5000/todos -d "task=something new" -X POST -v

更新一个任务：

$ curl http://localhost:5000/todos/todo3 -d "task=something different" -X PUT -v