Python3连接MySQL（pymysql）模拟转账实现代码

本文实例为大家分享了Python3连接MySQL模拟转账的具体实现代码，供大家参考，具体内容如下

# coding:utf8
import sys
import pymysql

class TransferMoney(object):
 def __init__(self,conn):
   self.conn=conn

def check_acct_available(self,acctid):
   cursor = self.conn.cursor()
   try:
     sql="select * from account where acctid=％s" ％ acctid
     cursor.execute(sql)
     print ("check_acct_available:" + sql)
     rs = cursor.fetchall()
     if len(rs) ! = 1:
       raise Exception("账号％s不存在"％ acctid)
   finally:
     cursor.close()

def has_enough_money(self,acctid,money):
   cursor = self.conn.cursor()
   try:
     sql="select * from account where acctid=％s and money>％s" ％ (acctid,money)
     cursor.execute(sql)
     print ("has_enough_money:"+sql)
     rs = cursor.fetchall()
     if len(rs) ! = 1:
       raise Exception("账号％s余额不足"％ acctid)
   finally:
     cursor.close()

def reduce_money(self,acctid,money):
   cursor = self.conn.cursor()
   try:
     sql = "update account set money=money-％s where acctid=％s" ％ (money,acctid)
     cursor.execute(sql)
     print ("reduce_money:"+sql)
     if cursor.rowcount ! = 1:
       raise Exception("账号％s减款失败" ％ acctid)
   finally:
     cursor.close()

def add_money(self,acctid,money):
   cursor = self.conn.cursor()
   try:
     sql="update account set money=money+％s where acctid=％s" ％ (money,acctid)
     cursor.execute(sql)
     print ("add_money:"+sql)
     if cursor.rowcount ! = 1:
       raise Exception("账号％s加款失败" ％ acctid)
   finally:
     cursor.close()

def transfer(self,source_acctid,target_acctid,money):
   try:
     self.check_acct_available(source_acctid)
     self.check_acct_available(target_acctid)
     self.has_enough_money(source_acctid,money)
     self.reduce_money(source_acctid,money)
     self.add_money(target_acctid,money)
     self.conn.commit()
   except Exception as e:
     self.conn.rollback()
     raise e

if __name__ == "__main__":
 source_acctid = sys.argv[1]
 target_acctid = sys.argv[2]
 money = sys.argv[3]

conn = pymysql.Connect(
           host = 'localhost',
           unix_socket = "..mysql/mysql.sock",
           port = 3306,
           user = 'root',
           passwd = '',
           db = 'python_db',
                   )
 tr_money = TransferMoney(conn)

try:
   tr_money.transfer(source_acctid,target_acctid,money)
 except Exception as e:
   print ("出现问题" + str(e))
 finally:
   conn.close()