括号不匹配
```python
def cal_max_ret(df,close,open,benchmark_close,benchmark_open,N):
ret = df.groupby('instrument',as_index=False,sort=False,group_keys=False).apply(lambda x:(pd.concat([x['close'].shift(-i)/ x['open']- x['benchmark_close'].shift(-i)/ x['benchmark_open'] for i in range(N)],axis=1)))
return ret
def cal_max_ret_datel(df,close,open,benchmark_close,benchmark_open,N):
ret = df.groupby ('instrument',as_index=False,sort=False,group_keys=False).apply(lambda x:(pd.concat([x['close'].shift(-i)/ x['open']- x['benchmark_close'].shift(-i)/ x['benchmark_open'] for i in range(N)],axis=1)))
return np.nanargmax(np.array(ret),axis=1)
bigquant_run={'cal_max_ret':cal_max_ret,'cal_max_ret_date': cal_max_ret_datel}
```
\