一 简介
Python和MySQL交互的模块有 MySQLdb 和 PyMySQL(pymysql),MySQLdb是基于C 语言编写的，而且Python3 不在支持MySQLdb 。PyMySQL是一个纯Python写的MySQL客户端，它的目标是替代MySQLdb，可以在CPython、PyPy、IronPython和Jython环境下运行,PyMySQL在MIT许可下发布。
在开发基于Python语言的项目中，为了以后系统能兼容Python3,我们使用了PyMySQL替换了MySQLdb。下面我们来熟悉一下pymysql的使用。

二 安装方式
pymsql的源码 https://github.com/PyMySQL/PyMySQL ，目前还在持续更新。

安装要求:

Python -- one of the following:

CPython >= 2.6 or >= 3.3

PyPy >= 4.0

IronPython 2.7

MySQL Server -- one of the following:

MySQL >= 4.1 (tested with only 5.5~)

MariaDB >= 5.1

安装

pip install PyMySQL

三 基于pymysql的数据库交互

#!/usr/bin/env python

# encoding: utf-8

"""

author: yangyi@youzan

time:2015/6/8 上午11:34

func: 基于pymysql的数据库交互类，支持事务提交和回滚，返回结果记录行数，和insert的最新id

"""

import pymysql

from warnings import filterwarnings

filterwarnings('ignore', category=pymysql.Warning)

CONNECT_TIMEOUT = 100

IP = 'localhost'

PORT = 3306

USER = 'root'

PASSSWORD = ''

class QueryException(Exception):

"""

"""

class ConnectionException(Exception):

"""

"""

class MySQL_Utils():

def __init__(

self, ip=IP, port=PORT, user=USER, password=PASSSWORD,

connect_timeout=CONNECT_TIMEOUT, remote=False, socket='', dbname='test'):

self.__conn = None

self.__cursor = None

self.lastrowid = None

self.connect_timeout = connect_timeout

self.ip = ip

self.port = port

self.user = user

self.password = password

self.mysocket = socket

self.remote = remote

self.db = dbname

self.rows_affected = 0

def __init_conn(self):

try:

conn = pymysql.connect(

host=self.ip,

port=int(self.port),

user=self.user,

db=self.db,

connect_timeout=self.connect_timeout,

charset='utf8', unix_socket=self.mysocket)

except pymysql.Error as e:

raise ConnectionException(e)

self.__conn = conn

def __init_cursor(self):

if self.__conn:

self.__cursor = self.__conn.cursor(pymysql.cursors.DictCursor)

def close(self):

if self.__conn:

self.__conn.close()

self.__conn = None

#专门处理select 语句

def exec_sql(self, sql, args=None):

try:

if self.__conn is None:

self.__init_conn()

self.__init_cursor()

self.__conn.autocommit = True

self.__cursor.execute(sql, args)

self.rows_affected = self.__cursor.rowcount

results = self.__cursor.fetchall()

return results

except pymysql.Error as e:

raise pymysql.Error(e)

finally:

if self.__conn:

self.close()

# 专门处理dml语句 delete，updete，insert

def exec_txsql(self, sql, args=None):

try:

if self.__conn is None:

self.__init_conn()

self.__init_cursor()

if self.__cursor is None:

self.__init_cursor()

self.rows_affected=self.__cursor.execute(sql, args)

self.lastrowid = self.__cursor.lastrowid

returnself.rows_affected

except pymysql.Error as e:

raise pymysql.Error(e)

finally:

if self.__cursor:

self.__cursor.close()

self.__cursor = None

# 提交

def commit(self):

try:

if self.__conn:

self.__conn.commit()

except pymysql.Error as e:

raise pymysql.Error(e)

finally:

if self.__conn:

self.close()

#回滚操作

def rollback(self):

try:

if self.__conn:

self.__conn.rollback()

except pymysql.Error as e:

raise pymysql.Error(e)

finally:

if self.__conn:

self.close()

# 适用于需要获取插入记录的主键自增id

def get_lastrowid(self):

return self.lastrowid

#获取dml操作影响的行数
def get_affectrows(self):
return self.rows_affected
#MySQL_Utils初始化的实例销毁之后，自动提交
def __del__(self):
self.commit()