ERC代币标准：从USB接口到万能转接头的资产进化史

"""MiniToken: 用 Python 模拟 ERC-20 / ERC-721 / ERC-1155 的核心账本逻辑纯教学演示，用 dict 模拟链上状态存储"""from typing import Dict, Tuple  class ERC20Simulator:    """模拟 ERC-20 同质化代币的账本"""     def __init__(self, name: str, symbol: str, total_supply: int):        self.name = name        self.symbol = symbol        self.total_supply = total_supply        self.balances: Dict[str, int] = {}        self.allowances: Dict[Tuple[str, str], int] = {}        self._mint("0x0", total_supply)     def _mint(self, to: str, amount: int) -> None:        """内部铸造函数，把新代币记入指定账户"""        self.balances[to] = self.balances.get(to, 0) + amount     def balance_of(self, owner: str) -> int:        """查询余额, 对应 ERC-20 的 balanceOf"""        return self.balances.get(owner, 0)     def transfer(self, sender: str, to: str, value: int) -> bool:        """直接转账, 对应 ERC-20 的 transfer"""        if self.balances.get(sender, 0) < value:            raise ValueError("insufficient balance")        self.balances[sender] -= value        self.balances[to] = self.balances.get(to, 0) + value        return True     def approve(self, owner: str, spender: str, value: int) -> bool:        """授权第三方可花费额度, 对应 ERC-20 的 approve"""        self.allowances[(owner, spender)] = value        return True     def transfer_from(self, spender: str, owner: str, to: str, value: int) -> bool:        """代扣转账, 对应 ERC-20 的 transferFrom"""        allowance = self.allowances.get((owner, spender), 0)        if allowance < value:            raise ValueError("allowance exceeded")        self.transfer(owner, to, value)        self.allowances[(owner, spender)] = allowance - value        return True  class ERC721Simulator:    """模拟 ERC-721 非同质化代币的所有权映射"""     def __init__(self, name: str, symbol: str):        self.name = name        self.symbol = symbol        self.token_owner: Dict[int, str] = {}        self.owner_tokens: Dict[str, list] = {}        self._next_id = 1     def mint(self, to: str) -> int:        """铸造一枚新的NFT, 返回唯一的 tokenId"""        token_id = self._next_id        self._next_id += 1        self.token_owner[token_id] = to        self.owner_tokens.setdefault(to, []).append(token_id)        return token_id     def owner_of(self, token_id: int) -> str:        """查询NFT当前所有者, 对应 ERC-721 的 ownerOf"""        if token_id not in self.token_owner:            raise ValueError("token does not exist")        return self.token_owner[token_id]     def transfer(self, from_addr: str, to: str, token_id: int) -> bool:        """转移NFT所有权, 模拟 ERC-721 的 transferFrom"""        if self.token_owner.get(token_id) != from_addr:            raise ValueError("not the owner")        self.token_owner[token_id] = to        self.owner_tokens[from_addr].remove(token_id)        self.owner_tokens.setdefault(to, []).append(token_id)        return True  class ERC1155Simulator:    """模拟 ERC-1155 多代币批量账本"""     def __init__(self) -> None:        self.balances: Dict[Tuple[str, int], int] = {}     def mint(self, to: str, token_id: int, amount: int) -> None:        key = (to, token_id)        self.balances[key] = self.balances.get(key, 0) + amount     def balance_of(self, account: str, token_id: int) -> int:        """查询某账户对某代币的余额"""        return self.balances.get((account, token_id), 0)     def batch_transfer(self, from_addr: str, to: str,                       ids: list, amounts: list) -> bool:        """批量转移多种代币, 对应 ERC-1155 的 safeBatchTransferFrom"""        for tid, amt in zip(ids, amounts):            key_from = (from_addr, tid)            if self.balances.get(key_from, 0) < amt:                raise ValueError("insufficient balance")        for tid, amt in zip(ids, amounts):            self.balances[(from_addr, tid)] -= amt            self.balances[(to, tid)] = self.balances.get((to, tid), 0) + amt        return True  if __name__ == "__main__":    # ERC-20 演示: 转账与授权    token = ERC20Simulator("DemoCoin", "DMC", 10000)    token.transfer("0x0", "0xAlice", 500)    token.approve("0xAlice", "0xDEX", 200)    token.transfer_from("0xDEX", "0xAlice", "0xBob", 150)    print(f"Alice余额: {token.balance_of('0xAlice')}")    print(f"Bob余额: {token.balance_of('0xBob')}")     # ERC-721 演示: 铸造与转移 NFT    nft = ERC721Simulator("DemoNFT", "DNFT")    nid = nft.mint("0xCarol")    print(f"NFT #{nid} 所有者: {nft.owner_of(nid)}")    nft.transfer("0xCarol", "0xDave", nid)    print(f"转移后所有者: {nft.owner_of(nid)}")     # ERC-1155 演示: 批量转移    multi = ERC1155Simulator()    multi.mint("0xEve", 1, 10)    multi.mint("0xEve", 2, 3)    multi.batch_transfer("0xEve", "0xFrank", [1, 2], [4, 1])    print(f"Frank 的 ID1 余额: {multi.balance_of('0xFrank', 1)}")    print(f"Frank 的 ID2 余额: {multi.balance_of('0xFrank', 2)}")