flask + MySQL-python 创建 webapp 应用

0 - python 用自带的 wgsi 也可以创建 web 服务
1)建立 hello.py 内容如下
# hello.py
def application(environ, start_response):
start_response('200 OK', [('Content-Type', 'text/html')])
return '<h1>Hello, web!</h1>'
2)建立 server.py
# -*- coding:utf-8 -*-
# 从wsgiref模块导入:
from wsgiref.simple_server import make_server
# 导入我们自己编写的application函数:
from hello import application
# 创建一个服务器,IP地址为空,端口是8000,处理函数是application:
httpd = make_server('', 8000, application)
print "Serving HTTP on port 8000..."
# 开始监听HTTP请求:
httpd.serve_forever()

缺点:貌似只能创建一个访问地址,不同 url 路由不好控制

1 - flask 建立一个 web server


1、pip install Flask
2、建立一个 test_flask.py 的文件,加入代码如下:

# -*- coding:utf-8 –*-
from flask import Flask, request, make_response, current_app
from functools import wraps
import json
import sys
import datetime

# 一个 app 是一个 Flask 文件 
app = Flask(__name__)
def jsonp(func):
  """Wraps JSONified output for JSONP requests."""
  @wraps(func)
  def decorated_function(*args, **kwargs):
    callback = request.args.get('callback', False)
    if callback:
      data = str(func(*args, **kwargs).data)
      content = str(callback) + '(' + data + ')'
      mimetype = 'application/javascript'
      return current_app.response_class(content, mimetype=mimetype)
    else:
      return func(*args, **kwargs)
    return decorated_function

# 有route

@app.route('/test', methods=['GET'])
def test():
  resp = make_response(
    (
      json.dumps({'key':'value'}),
      200,
      {'Content-Type': 'application/json'}
    )
  )
  return resp

if __name__ == '__main__':
  app.run(host='0.0.0.0', port=8899)

2 - 安装mysql 


1、使用 brew 安装 mysql 服务
brew install mysql
2、启动 mysql 服务
mysql.server start
3、使用 root 用户免密登录
mysql -uroot
4、修改 root 密码
SET PASSWORD FOR 'root'@'localhost' = PASSWORD('newpass');
5、登录 mysql 数据库 建立测试表格
create table tb_dept(
id int primary key auto_increment,#部门编号 整形 主键 自增长
name varchar(18),#部门名称
description varchar(100)#描述
);

3 - 安装 MySQL-python

pip install MySQL-python

4 - 手写数据库连接代码

# -*- coding:utf-8 –*-
from flask import Flask, request, make_response, current_app
from functools import wraps
import MySQLdb as mysql
import json
import sys
import datetime
app = Flask(__name__)

def MysqlInit():
  #connect to mysql
  hostaddress = 'localhost'
  username = 'root'
  password = '*****'
  database = 'test'
  try:
    conn = mysql.connect(
      host=hostaddress,
      user=username,
      passwd=password,
      db=database,
      charset="utf8")
      print 'connect to mysql db success'
      return conn
    except Exception, e:
      print e
      sys.exit('init mysql failed!')


def CheckConnect(conn):
  try:
    conn.ping()
    return conn
  except:
    print 'mysql coonect has been closed now reconnect'
    cur_conn = MysqlInit()
  return cur_conn

def QueryClusterInfo(conn):
  print " coming QueryClusterInfo!!!"
  try:
    conn = CheckConnect(conn)
    cursor = conn.cursor()
  except:
    conn = CheckConnect(conn)
    cursor = conn.cursor()
    response_dict = {'ret_code':0,'ret_msg':'ok'}

    sql_cmd = 'select * from tb_dept'

  try:
    cursor.execute(sql_cmd)
    cluster_result = cursor.fetchall()
  except:
    cursor.close()
    response_dict['ret_code'] = 1
    response_dict['ret_msg'] = 'sql_select_error_in_queryClusterInfo'
    return json.dumps(response_dict)
  response_dict['res'] = []

  if cluster_result is not None:
    for items in cluster_result:
      res = {}
      res['id'] = items[0]
      res['name'] = items[1]
      res['description'] = items[2]
      response_dict['res'].append(res)
    cursor.close()
    return json.dumps(response_dict)

def jsonp(func):
  """Wraps JSONified output for JSONP requests."""
  @wraps(func)
  def decorated_function(*args, **kwargs):
    callback = request.args.get('callback', False)
    if callback:
      data = str(func(*args, **kwargs).data)
      content = str(callback) + '(' + data + ')'
      mimetype = 'application/javascript'
      return current_app.response_class(content, mimetype=mimetype)
    else:
      return func(*args, **kwargs)
    return decorated_function

@app.route('/test_mysql', methods=['GET'])
def test():
  conn = MysqlInit()
  resp = make_response(
    (
      QueryClusterInfo(conn),
      200,
      {'Content-Type': 'application/json'}
    )
  )
  return resp

if __name__ == '__main__':
  app.run(host='0.0.0.0', port=8989)

原文地址:https://www.cnblogs.com/oftenlin/p/8552030.html