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()

以上就是本文的全部内容，希望对大家学习python程序设计有所帮助。