用 python + flask 做一个实现基本 CRUD 的 rest api

环境 win10 64 bit , python 3.6

先建立一个虚拟目录

virtualenv venv

1	virtualenv venv

进入所建立虚拟目录的scripts 目录，执行

activate

activate

pip install flask flask-jsonpify flask-sqlalchemy flask-restful

1	pip install flask flask-jsonpify flask-sqlalchemy flask-restful

安装完成后执行

pip freeze

1	pip freeze

查看所安装的版本

在跟目录新建一个python 脚本，命名为 app.py

from flask import Flask
app = Flask(__name__)

@app.route("/")
def hello():
    return "Hello World!"

from flask import Flask

app = Flask(__name__)

@app.route("/")

def hello():

return "Hello World!"

设置默认启动的脚本

set FLASK_APP=app.py

1	set FLASK_APP=app.py

启动

flask run

flask run

之后用浏览器访问web service ,即可看到返回结果

接下来，如果实现 CRUD api

新建脚本，取名为 hello.py

from flask import Flask, request
from flask_restful import Resource, Api
from sqlalchemy import create_engine
from json import dumps
from flask_jsonpify import jsonify

db_connect = create_engine('sqlite:///chinook.db')
app = Flask(__name__)
api = Api(app)

class Employees(Resource):
    def get(self):
        conn = db_connect.connect() # connect to database
        query = conn.execute("select * from employees") # This line performs query and returns json result
        return {'employees': [i[0] for i in query.cursor.fetchall()]} # Fetches first column that is Employee ID

class Tracks(Resource):
    def get(self):
        conn = db_connect.connect()
        query = conn.execute("select trackid, name, composer, unitprice from tracks;")
        result = {'data': [dict(zip(tuple (query.keys()) ,i)) for i in query.cursor]}
        return jsonify(result)

class Employees_Name(Resource):
    def get(self, employee_id):
        conn = db_connect.connect()
        query = conn.execute("select * from employees where EmployeeId =%d "  %int(employee_id))
        result = {'data': [dict(zip(tuple (query.keys()) ,i)) for i in query.cursor]}
        return jsonify(result)
        

api.add_resource(Employees, '/employees') # Route_1
api.add_resource(Tracks, '/tracks') # Route_2
api.add_resource(Employees_Name, '/employees/<employee_id>') # Route_3


if __name__ == '__main__':
     app.run(port='5002')

from flask import Flask, request

from flask_restful import Resource, Api

from sqlalchemy import create_engine

from json import dumps

from flask_jsonpify import jsonify

db_connect = create_engine('sqlite:///chinook.db')

app = Flask(__name__)

api = Api(app)

class Employees(Resource):

def get(self):

conn = db_connect.connect() # connect to database

query = conn.execute("select * from employees") # This line performs query and returns json result

return {'employees': [i[0] for i in query.cursor.fetchall()]} # Fetches first column that is Employee ID

class Tracks(Resource):

def get(self):

conn = db_connect.connect()

query = conn.execute("select trackid, name, composer, unitprice from tracks;")

result = {'data': [dict(zip(tuple (query.keys()) ,i)) for i in query.cursor]}

return jsonify(result)

class Employees_Name(Resource):

def get(self, employee_id):

conn = db_connect.connect()

query = conn.execute("select * from employees where EmployeeId =%d " %int(employee_id))

result = {'data': [dict(zip(tuple (query.keys()) ,i)) for i in query.cursor]}

return jsonify(result)

api.add_resource(Employees, '/employees') # Route_1

api.add_resource(Tracks, '/tracks') # Route_2

api.add_resource(Employees_Name, '/employees/<employee_id>') # Route_3

if __name__ == '__main__':

app.run(port='5002')

设置为默认启动脚本

set FLASK_APP=helo.py

1	set FLASK_APP=helo.py

从 http://www.sqlitetutorial.net/sqlite-sample-database/

下载 sqlite example 数据库： chinook.db ,copy 到 hello.py 同目录

启动flask

flask run

flask run

此时打开浏览器

http://127.0.0.1:5000/tracks

1	http://127.0.0.1:5000/tracks

即可看到 tracks 表的所有记录

到目前为止，只是实现了查询

参考资料

https://www.codementor.io/sagaragarwal94/building-a-basic-restful-api-in-python-58k02xsiq

大部分对，但是这句

from flask.ext.jsonpify import jsonify

1	from flask.ext.jsonpify import jsonify

不对，在我的环境应为

from flask_jsonpify import jsonify

1	from flask_jsonpify import jsonify

sqlite3 工具下载 https://www.sqlite.org/download.html

sqlite example 数据库下载

http://www.sqlitetutorial.net/sqlite-sample-database/