Flask-RESTful 是一个 Flask 扩展，它添加了快速构建 REST APIs 的支持。它当然也是一个能够跟你现有的ORM/库协同工作的轻量级的扩展。Flask-RESTful 鼓励以最小设置的最佳实践。如果你熟悉 Flask 的话，Flask-RESTful 应该很容易上手。
关于flask的使用，参考我的之前的博客：https://blog.csdn.net/shifengboy/article/details/114274271
flask-restful官方文档：https://flask-restful.readthedocs.io/en/lates
中文文档：http://www.pythondoc.com/Flask-RESTful/
flask-restful 安装
pip install flask-restful
flask-restful使用
简单上手
from flask import Flask
from flask_restful import Resource, Api
app = Flask(__name__)
api = Api(app)
class HelloWorld(Resource):
def get(self):
return {'hello': 'world'}
api.add_resource(HelloWorld, '/')
if __name__ == '__main__':
app.run(debug=True)
运行结果：
$ curl http://127.0.0.1:5000/
{"hello": "world"}
Resourceful 路由
Flask-RESTful 提供的主要构建块是资源。资源构建在 Flask 可插入视图之上，只需在资源上定义方法，就可以轻松访问多个 HTTP 方法。一个 todo 应用程序的基本 CRUD 资源是这样的:
from flask import Flask, request
from flask_restful import Resource, Api
app = Flask(__name__)
api = Api(app)
todos = {}
class TodoSimple(Resource):
def get(self, todo_id):
return {todo_id: todos[todo_id]}
def put(self, todo_id):
todos[todo_id] = request.form['data']
return {todo_id: todos[todo_id]}
api.add_resource(TodoSimple, '/<string:todo_id>')
if __name__ == '__main__':
app.run(debug=True)
运行结果：
chenshifengdeMacBook-Pro:~ chenshifeng$ curl http://localhost:5000/todo1 -d "data=Remember the milk" -X PUT
{
"todo1": "Remember the milk"
}
chenshifengdeMacBook-Pro:~ chenshifeng$ curl http://localhost:5000/todo1
{
"todo1": "Remember the milk"
}
chenshifengdeMacBook-Pro:~ chenshifeng$ curl http://localhost:5000/todo2 -d "data=Change my brakepads" -X PUT
{
"todo2": "Change my brakepads"
}
chenshifengdeMacBook-Pro:~ chenshifeng$ curl http://localhost:5000/todo2
{
"todo2": "Change my brakepads"
}
chenshifengdeMacBook-Pro:~ chenshifeng$
Restful 能够从 view 方法中理解多种返回值。类似于 Flask，你可以返回任何可迭代的并且它将被转换成一个响应，包括原始 Flask 响应对象。还支持使用多个返回值设置响应代码和响应头，如下所示:
#!/usr/bin/python
# -*- coding: UTF-8 -*-
"""
@author:chenshifeng
@file:flask_restful_demo.py
@time:2021/03/05
"""
from flask import Flask, request
from flask_restful import Resource, Api
app = Flask(__name__)
api = Api(app)
class Todo1(Resource):
def get(self):
# Default to 200 OK
return {'task': 'Hello world'}
class Todo2(Resource):
def get(self):
# Set the response code to 201
return {'task': 'Hello world'}, 201
class Todo3(Resource):
def get(self):
# Set the response code to 201 and return custom headers
return {'task': 'Hello world'}, 201, {'Etag': 'some-opaque-string'}
api.add_resource(Todo1,'/todo1')
api.add_resource(Todo2,'/todo2')
api.add_resource(Todo3,'/todo3')
if __name__ == '__main__':
app.run(debug=True)
运行结果：
chenshifengdeMacBook-Pro:~ chenshifeng$ curl -i http://127.0.0.1:5000/todo1
HTTP/1.0 200 OK
Content-Type: application/json
Content-Length: 30
Server: Werkzeug/1.0.1 Python/3.9.2
Date: Fri, 05 Mar 2021 16:08:28 GMT
{
"task": "Hello world"
}
chenshifengdeMacBook-Pro:~ chenshifeng$ curl -i http://127.0.0.1:5000/todo2
HTTP/1.0 201 CREATED
Content-Type: application/json
Content-Length: 30
Server: Werkzeug/1.0.1 Python/3.9.2
Date: Fri, 05 Mar 2021 16:08:32 GMT
{
"task": "Hello world"
}
chenshifengdeMacBook-Pro:~ chenshifeng$ curl -i http://127.0.0.1:5000/todo3
HTTP/1.0 201 CREATED
Content-Type: application/json
Content-Length: 30
Etag: some-opaque-string
Server: Werkzeug/1.0.1 Python/3.9.2
Date: Fri, 05 Mar 2021 16:08:34 GMT
{
"task": "Hello world"
}
chenshifengdeMacBook-Pro:~ chenshifeng$
Endpoints 端点
很多时候，在一个 API 中，你的资源会有多个 url。可以将多个 url 传递给 Api 对象上的 add _ resource ()方法。每一个都将被路由到Resource
api.add_resource(HelloWorld,
'/',
'/hello')
您还可以将路径的某些部分作为变量匹配到Resource。
api.add_resource(Todo,
'/todo/<int:todo_id>', endpoint='todo_ep')
演示代码：
from flask import Flask
from flask_restful import Resource, Api
app = Flask(__name__)
api = Api(app)
class HelloWorld(Resource):
def get(self):
return {'hello': 'world'}
class Todo(Resource):
def get(self, todo_id):
# Default to 200 OK
return {'task': 'Hello world'}
api.add_resource(HelloWorld, '/', '/hello')
api.add_resource(Todo, '/todo/<int:todo_id>', endpoint='todo_ep')
if __name__ == '__main__':
app.run(debug=True)
演示结果：
chenshifengdeMacBook-Pro:~ chenshifeng$ curl http://127.0.0.1:5000/
{
"hello": "world"
}
chenshifengdeMacBook-Pro:~ chenshifeng$ curl http://127.0.0.1:5000/hello
{
"hello": "world"
}
chenshifengdeMacBook-Pro:~ chenshifeng$ curl http://127.0.0.1:5000/todo/1
{
"task": "Hello world"
}
chenshifengdeMacBook-Pro:~ chenshifeng$ curl http://127.0.0.1:5000/todo/2
{
"task": "Hello world"
}
参数解析
虽然 Flask 可以方便地访问请求数据(即 querystring 或 POST 表单编码的数据) ，但验证表单数据仍然是一件痛苦的事情。使用类似于 argparse 的库对请求数据验证提供内置支持。
from flask import Flask
from flask_restful import reqparse, Api, Resource
app = Flask(__name__)
api = Api(app)
parser = reqparse.RequestParser()
parser.add_argument('rate', type=int, help='Rate to charge for this resource')
class Todo(Resource):
def post(self):
args = parser.parse_args()
print(args)
# Default to 200 OK
return {'task': 'Hello world'}
api.add_resource(Todo,'/todos' )
if __name__ == '__main__':
app.run(debug=True)
chenshifengdeMacBook-Pro:~ chenshifeng$ curl -d 'rate=100' http://127.0.0.1:5000/todos
{
"task": "Hello world"
}
chenshifengdeMacBook-Pro:~ chenshifeng$ curl -d 'rate=foo' http://127.0.0.1:5000/todos
{
"message": {
"rate": "Rate to charge for this resource"
}
}
输入模块提供了许多常用的转换函数，例如 inputs.date ()和 inputs.url ()。
使用 strict = True 调用 parse _ args 可以确保在请求包含您的解析器没有定义的参数时抛出错误。
args = parser.parse_args(strict=True)
$ curl -d 'rate2=foo' http://127.0.0.1:5000/todos
{
"message": "Unknown arguments: rate2"
}
数据格式化
默认情况下，在你的返回迭代中所有字段将会原样呈现。尽管当你刚刚处理 Python 数据结构的时候，觉得这是一个伟大的工作，但是当实际处理它们的时候，会觉得十分沮丧和枯燥。为了解决这个问题，Flask-RESTful 提供了 fields 模块和 marshal_with() 装饰器。类似 Django ORM 和 WTForm，你可以使用 fields 模块来在你的响应中格式化结构。
from flask import Flask
from flask_restful import fields, marshal_with, Resource, Api
app = Flask(__name__)
api = Api(app)
resource_fields = {
'task': fields.String,
'uri': fields.Url('todo')
}
class TodoDao(object):
def __init__(self, todo_id, task):
self.todo_id = todo_id
self.task = task
# This field will not be sent in the response
self.status = 'active'
class Todo(Resource):
@marshal_with(resource_fields)
def get(self, **kwargs):
return TodoDao(todo_id='my_todo', task='Remember the milk')
api.add_resource(Todo,'/todo')
if __name__ == '__main__':
app.run(debug=True)
上面的例子接受一个 python 对象并准备将其序列化。marshal_with() 装饰器将会应用到由 resource_fields 描述的转换。从对象中提取的唯一字段是 task。fields.Url 域是一个特殊的域，它接受端点（endpoint）名称作为参数并且在响应中为该端点生成一个 URL。许多你需要的字段类型都已经包含在内。请参阅 fields 指南获取一个完整的列表。
$ curl http://127.0.0.1:5000/todo
{
"task": "Remember the milk",
"uri": "/todo"
}
完整例子
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)
获取列表
$ curl http://localhost:5000/todos
{
"todo1": {
"task": "build an API"
},
"todo2": {
"task": "?????"
},
"todo3": {
"task": "profit!"
}
}
获取一个单独的任务
$ curl http://localhost:5000/todos/todo3
{
"task": "profit!"
}
删除一个任务
$ curl http://localhost:5000/todos/todo2 -X DELETE -v
* Trying ::1...
* TCP_NODELAY set
* Connection failed
* connect to ::1 port 5000 failed: Connection refused
* Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 5000 (#0)
> DELETE /todos/todo2 HTTP/1.1
> Host: localhost:5000
> User-Agent: curl/7.64.1
> Accept: */*
>
* HTTP 1.0, assume close after body
< HTTP/1.0 204 NO CONTENT
< Content-Type: application/json
< Server: Werkzeug/1.0.1 Python/3.9.2
< Date: Sat, 06 Mar 2021 03:29:33 GMT
<
* Closing connection 0
增加一个新的任务
$ curl http://localhost:5000/todos -d "task=something new" -X POST -v
Note: Unnecessary use of -X or --request, POST is already inferred.
* Trying ::1...
* TCP_NODELAY set
* Connection failed
* connect to ::1 port 5000 failed: Connection refused
* Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 5000 (#0)
> POST /todos HTTP/1.1
> Host: localhost:5000
> User-Agent: curl/7.64.1
> Accept: */*
> Content-Length: 18
> Content-Type: application/x-www-form-urlencoded
>
* upload completely sent off: 18 out of 18 bytes
* HTTP 1.0, assume close after body
< HTTP/1.0 201 CREATED
< Content-Type: application/json
< Content-Length: 32
< Server: Werkzeug/1.0.1 Python/3.9.2
< Date: Sat, 06 Mar 2021 03:31:02 GMT
<
{
"task": "something new"
}
* Closing connection 0
更新一个任务
$ curl http://localhost:5000/todos/todo3 -d "task=something different" -X PUT -v
* Trying ::1...
* TCP_NODELAY set
* Connection failed
* connect to ::1 port 5000 failed: Connection refused
* Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 5000 (#0)
> PUT /todos/todo3 HTTP/1.1
> Host: localhost:5000
> User-Agent: curl/7.64.1
> Accept: */*
> Content-Length: 24
> Content-Type: application/x-www-form-urlencoded
>
* upload completely sent off: 24 out of 24 bytes
* HTTP 1.0, assume close after body
< HTTP/1.0 201 CREATED
< Content-Type: application/json
< Content-Length: 38
< Server: Werkzeug/1.0.1 Python/3.9.2
< Date: Sat, 06 Mar 2021 03:32:44 GMT
<
{
"task": "something different"
}
* Closing connection 0
获取最新列表
$ curl http://localhost:5000/todos
{
"todo1": {
"task": "build an API"
},
"todo3": {
"task": "something different"
},
"todo4": {
"task": "something new"
}
}