秒合约交易规则比较简捷，简单来说，首先必须选择要交易的数字货币。交易时间区间短为1min、3min、5min，长为60min；然后风险控制，在我们可以控制的风险范围内设定交易金额，设定盈余止损，最重要的是进行货币方向走势的技术分析。也就是说，在我们设置的交易区间内的涨跌方向，根据分析下单。
当指定了trade_id时, 返回一个成交Trade对象引用，不填trade_id参数调用本函数, 将返回包含用户当前交易日所有成交记录的一个Entity对象引用, 使用方法与dict一致, 其中每个元素的key为成交号, value为Trade，Trade继承于Entity。推荐优先使用 Order对象的属性trade_records获取某个委托单的相应成交记录, 更简单易用，仅当确有需要时才使用本函数。
is_changing(obj: Any, key: Optional[Union[str, List[str]]] = None)：判定obj最近是否有更新。当业务数据更新导致 wait_update 返回后可以使用该函数判断本次业务数据更新是否包含特定obj或其中某个字段 。如果本次业务数据更新包含了待判定的数据则返回 True, 否则返回 False。关于判断K线更新的说明： 当生成新K线时，其所有字段都算作有更新，若此时执行 api.is_changing(klines.iloc[-1]) 则一定返回True。
* @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
* @param _spender The address which will spend the funds.
* @param _value The amount of tokens to be spent.
*/
function approve(address _spender, uint _value) public onlyPayloadSize(2 * 32) { // To change the approve amount you first have to reduce the addresses`
// allowance to zero by calling `approve(_spender, 0)` if it is not
// already 0 to mitigate the race condition described here:
//
require(!((_value != 0) && (allowed[msg.sender][_spender] != 0)));
allowed[msg.sender][_spender] = _value;
Approval(msg.sender, _spender, _value);
} /**
* @dev Function to check the amount of tokens than an owner allowed to a spender.
* @param _owner address The address which owns the funds.
* @param _spender address The address which will spend the funds.
* @return A uint specifying the amount of tokens still available for the spender.
*/
function allowance(address _owner, address _spender) public constant returns (uint remaining) { return allowed[_owner][_spender];
}
}/**
* @title Pausable
* @dev Base contract which allows children to implement an emergency stop mechanism.
*/contract Pausable is Ownable {
event Pause();
event Unpause(); bool public paused = false; /**
* @dev Modifier to make a function callable only when the contract is not paused.
*/
modifier whenNotPaused() { require(!paused);
_;
} /**
* @dev Modifier to make a function callable only when the contract is paused.
*/
modifier whenPaused() { require(paused);
_;
} /**
* @dev called by the owner to pause, triggers stopped state
*/
function pause() onlyOwner whenNotPaused public {
paused = true;
Pause();
} /**
* @dev called by the owner to unpause, returns to normal state
*/
function unpause() onlyOwner whenPaused public {
paused = false;
Unpause();
}
