python flask restful_Flask应用示例1 - 通过Flask实现Restful服务

1，前言

Python的强大，已经涉及到软件开发领域的方方面面。然而，Python入门容易，精确很难，需要深入研究。

在Web方面同样如此，常用的Python Web框架，例如Django、Flask、Tornado等等，共计有100多种，各有优劣。本文以Flask为例，介绍Flask的Restful实现方式，主要实现对数据表的增删查改操作。

2，需求

在开发代码之前，需要提前明确URL请求、HTTP方法与对应的动作。

2.1，Mysql数据表

创建一个简单的数据表，表名是student，存储学生的name、age、birth_time信息。

2.2，学生列表的操作

URL：http://127.0.0.1:5002/student/

get 获取学生列表

post 创建新学生信息

2.3，单个学生的操作

URL：http://127.0.0.1:5002/student/

get 获取单个学生信息

put 更新单个学生信息

delete 删除单个学生信息

2.4，附属功能

要求每次请求之前，记录用户的IP、请求参数等信息，便于统计分析

要求每次数据库操作，判断数据库连接是否正常，避免长时间未进行DB操作而造成DB连接失连

3，Flask项目

3.1，创建Flask项目

Windows可以使用PyCharm安装，或者手动安装

Ubuntu安装flask，执行 sudo apt-get install python-flask

创建hello.py，测试flask是否OK

from flask import Flask

app = Flask(__name__)

@app.route('/')

def hello_world():

return 'Hello World!'

if __name__ == '__main__':

app.run()

启动flask，执行 python hello.py

测试flask，执行 curl http://127.0.0.1:5000/，发现返回“Hello World!”，证明安装成功

如果返回缺少某些python包，莫急，逐个安装即可

3.2，目录规划

按照MVC的思想，对控制层和视图层进行分离。控制层主要是对数据库的处理，可以按照不同的数据表进行分文件处理；视图层，按照不同的功能模块，进行份文件处理。这样，便于项目维护和模块扩展。

不过，一定还有更好的目录规划方式，因项目或团队不同而不同，适合自己的即是最好的。

下面是初步划分的文件目录，可以参考。

D:\PYTEST\FLASK_TEST

│ ctrl_student.py # 视图层，响应URL请求

│ db_student.py # 控制层，数据库处理

│ flask_test.py # Flask主文件，控制URL路由

│ test.py # 测试文件

├─static

└─templates

4，源码

4.1，数据库表

student表结构

CREATE TABLE `student` (

`id` int(10) unsigned NOT NULL AUTO_INCREMENT,

`name` varchar(255) DEFAULT NULL,

`age` int(11) DEFAULT NULL,

`birth_time` datetime DEFAULT NULL,

`create_time` datetime DEFAULT NULL,

`is_del` int(10) unsigned zerofill DEFAULT '0000000000',

PRIMARY KEY (`id`)

) ENGINE=MyISAM AUTO_INCREMENT=19 DEFAULT CHARSET=utf8;

4.2，Python源码

flask_test.py

# coding:utf8

from flask import Flask, render_template, request

from flask_restful import Api

from ctrl_student import StudentList, Student

app = Flask(__name__)

api = Api(app)

api.add_resource(StudentList, '/student/')

api.add_resource(Student, '/student/')

@app.before_request

def before_request():

ip = request.remote_addr

url = request.url

form = request.form # 请求的数据，可执行searchword = request.form.get('key', '') ?????????测试(带参数的post请求)过程中form为空，不清楚原因

args = request.args # ?key=value，可执行searchword = request.args.get('key', '')

values = request.values # form和args的元组

headers = request.headers

method = request.method

path = request.path

base_url = request.base_url

url_root = request.url_root

print "ip", ip

print "url", url

# print "form", form

# print "args", args

# print "values", values

# print "headers", headers

# print "method", method

# print "path", path

# print "base_url", base_url

# print "url_root", url_root

@app.route('/')

def hello_world():

return 'Hello World!'

if __name__ == '__main__':

app.run(debug=True, host='0.0.0.0', port=5002)

ctrl_student.py

# coding:utf8

from flask_restful import reqparse, abort, Api, Resource

from db_student import DbStudent

# 404操作

def abort_if_todo_doesnt_exist(student_id):

if DbStudent.get_student_by_id(student_id) == {}:

abort(404, message="Todo {} doesn't exist".format(student_id))

# 入参解析器

parser = reqparse.RequestParser()

# parser.add_argument('id')

parser.add_argument('name')

parser.add_argument('age')

parser.add_argument('birth_time')

# 学生信息操作

class Student(Resource):

def __init__(self):

pass

# 获取student信息

def get(self, student_id):

abort_if_todo_doesnt_exist(student_id)

res = DbStudent.get_student_by_id(student_id)

return res, 200

# 更新student信息

def put(self, student_id):

print "put come in"

abort_if_todo_doesnt_exist(student_id)

args = parser.parse_args()

print args

DbStudent.update_student_by_id(student_id, args)

return {"status":"success"}, 200

# 删除student信息

def delete(self, student_id):

print "put come in"

abort_if_todo_doesnt_exist(student_id)

DbStudent.delete_student_by_id(student_id)

return {"status":"success"}, 200

# 兼容post操作，获取student信息

def post(self, student_id):

print "post come in"

return self.get(student_id)

# 学生列表操作

class StudentList(Resource):

# 获取学生信息列表

def get(self):

res = DbStudent.get_student_list()

return res, 200

# 增加单个学生信息

def post(self):

args = parser.parse_args()

DbStudent.insert_student(args)

return {"status":"success"}, 200

db_student.py

# coding:utf8

import MySQLdb

host = "192.168.1.64"

port = 3306

user = "******"

passwd = "******"

db = "test"

conn = None

cur = None

# 执行数据库操作之前判断数据库连接是否OK，如果异常则创建一次连接

def db_opt(func):

def db_ping():

global conn, cur

try:

cur.execute("select 1")

cur.fetchone()

except:

conn = MySQLdb.connect(host=host, port=port, user=user, passwd=passwd, db=db, charset="utf8")

cur = conn.cursor()

print "build a new connection"

def wrapper(*args, **kwargs):

global conn, cur

try:

db_ping()

res = func(*args, **kwargs)

print "db_opt", func, args, res

return res

except:

traceback.print_exc('wrapper ')

return {'status':False, 'data':'db operation maybe have some errors.'}

return wrapper

class DbStudent:

# 根据student_id获取学生信息

@staticmethod

@db_opt

def get_student_by_id(student_id):

sql = 'select id, name, age, birth_time from student where id = %s and is_del = 0' % student_id

cur.execute(sql)

res = cur.fetchall()

if len(res) == 0:

return {}

else:

(id, name, age, birth_time) = res[0]

dict_student ={}

dict_student['id'] = id

dict_student['name'] = name

dict_student['age'] = age

dict_student['birth_time'] = str(birth_time)

return dict_student

# 根据name获取学生信息

@staticmethod

@db_opt

def get_student_by_name(name):

sql = 'select id, name, age, birth_time from student where name = "%s" and is_del = 0' % name

cur.execute(sql)

res = cur.fetchall()

if len(res) == 0:

return {}

else:

(id, name, age, birth_time) = res[0]

dict_student = {}

dict_student['id'] = id

dict_student['name'] = name

dict_student['age'] = age

dict_student['birth_time'] = str(birth_time)

return dict_student

# 根据student_id更新学生信息

@staticmethod

@db_opt

def update_student_by_id(student_id, student_info):

sql = 'update student set name = "%s", age = %s, birth_time = "%s" where id = %s' % \

(student_info['name'], student_info['age'], student_info['birth_time'], student_id)

cur.execute(sql)

conn.commit

# 增加一条学生信息

@staticmethod

@db_opt

def insert_student(student_info):

sql = 'insert into student(name, age, birth_time, create_time) values("%s", %s, "%s", now())' % \

(student_info['name'], student_info['age'], student_info['birth_time'])

cur.execute(sql)

conn.commit

# 根据student_id删除学生信息(更新is_del字段)

@staticmethod

@db_opt

def delete_student_by_id(student_id):

sql = "update student set is_del = 1 where id = %s" % student_id

cur.execute(sql)

conn.commit

# 获取学生信息列表

@staticmethod

@db_opt

def get_student_list():

sql = 'select id, name, age, birth_time from student where is_del = 0'

cur.execute(sql)

res = cur.fetchall()

if len(res) == 0:

return {}

else:

student_list = []

for (id, name, age, birth_time) in res:

dict_student = {}

dict_student['id'] = id

dict_student['name'] = name

dict_student['age'] = age

dict_student['birth_time'] = str(birth_time)

student_list.append( dict_student )

return {"student_list": student_list}

if __name__ == '__main__':

print DbStudent.get_student_by_id(1)

print DbStudent.get_student_by_name('zhangsp')

print DbStudent.get_student_list()

5，测试

curl -X GET http://192.168.1.64:5002/student/

获取学生信息列表.png

增加1个学生信息

curl -H "Content-type: application/json" -X POST -d '{"age": 3, "birth_time": "2017-08-02 18:15:42", "name": "c"}' http://192.168.1.64:5002/student/

增加1个学生信息.png

更新单个学生信息

curl -H "Content-type: application/json" -X PUT -d '{"age": 333, "birth_time": "2017-08-02 18:15:42", "name": "c"}' http://192.168.1.64:5002/student/19

更新单个学生信息.png

删除单个学生信息

curl -H "Content-type: application/json" -X DELETE http://192.168.1.64:5002/student/19

删除单个学生信息.png

6，参考资料