区块链技术依托互联网时代而存在并发展，它的不可篡改的特性从根本上改变了中心化的信用创建方式，实现正常的系统运行。同时，杜绝冗余的节点和透明的数据处理方式，高效的实现人与人之间的互通。社会的发展离不开信任和高效，低效的工作一定会被高效所替代，不信任的关系也一定会被其他方式所取代。这也是为什么区块链技术被公认的将改变社会的一项技术。
notice Convert Tokens to ETH.
dev User specifies exact input and minimum output.
param tokens_sold Amount of Tokens sold.tokens_sold为要支付的代币数量
param min_eth Minimum ETH purchased.min_eth为要购买的ETH的最小值
param deadline Time after which this transaction can no longer be executed.
详细及功能案例I35分析7O98详细O7I8
return Amount of ETH bought.返回最终购买到的ETH数量
#函数功能：指定输入的代币数量，根据代币数量兑换ETH并发送给消息调用者
public关于区块链项目技术开发唯:MrsFu123，代币发行、dapp智能合约开发、链游开发、多链钱包开发
交易所开发、量化合约开发、互助游戏开发、Nft数字藏品开发、众筹互助开发、元宇宙开发、swap开发、
链上合约开发、ido开发、商城开发等，开发过各种各样的系统模式，更有多种模式、制度、案例、后台等，成熟技术团队，欢迎实体参考。
def tokenToEthSwapInput(tokens_sold:uint256,min_eth:uint256(wei),deadline:timestamp)->uint256(wei):
return self.tokenToEthInput(tokens_sold,min_eth,deadline,msg.sender,msg.sender)
notice Convert Tokens to ETH and transfers ETH to recipient.
dev User specifies exact input and minimum output.
param tokens_sold Amount of Tokens sold.
param min_eth Minimum ETH purchased.
param deadline Time after which this transaction can no longer be executed.
param recipient The address that receives output ETH.
return Amount of ETH bought.
#函数功能：指定输入的代币数量，根据代币数量兑换ETH并发送给指定接收者
比tokenToEthSwapInput函数多了一个接收者，指定用来接收所兑换的ETH的地址
public
def tokenToEthTransferInput(tokens_sold:uint256,min_eth:uint256(wei),deadline:timestamp,recipient:address)->uint256(wei):
assert recipient!=self and recipient!=ZERO_ADDRESS
return self.tokenToEthInput(tokens_sold,min_eth,deadline,msg.sender,recipient)
notice Convert Tokens to ETH.
dev User specifies maximum input and exact output.
param eth_bought Amount of ETH purchased.#想要购买的ETH的数量
param max_tokens Maximum Tokens sold.#最大能接受的支付的代币数量
param deadline Time after which this transaction can no longer be executed.
return Amount of Tokens sold.#最终消耗的代币数量
#函数功能：指定所想要兑换到的ETH数量并将ETH发送给消息调用者，函数根据要兑换的ETH计算扣除代币
public
def tokenToEthSwapOutput(eth_bought:uint256(wei),max_tokens:uint256,deadline:timestamp)->uint256:
return self.tokenToEthOutput(eth_bought,max_tokens,deadline,msg.sender,msg.sender)
notice Convert Tokens to ETH and transfers ETH to recipient.
dev User specifies maximum input and exact output.
param eth_bought Amount of ETH purchased.
param max_tokens Maximum Tokens sold.
param deadline Time after which this transaction can no longer be executed.
param recipient The address that receives output ETH.
return Amount of Tokens sold.
#函数功能：指定所想要兑换到的ETH数量并将ETH发送给指定接收者，函数根据要兑换的ETH计算扣除代币
public
def tokenToEthTransferOutput(eth_bought:uint256(wei),max_tokens:uint256,deadline:timestamp,recipient:address)->uint256:
assert recipient!=self and recipient!=ZERO_ADDRESS
return self.tokenToEthOutput(eth_bought,max_tokens,deadline,msg.sender,recipient)
