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()

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。