from datetime import datetime
from vnpy.trader.vtConstant import Exchange, Interval
from vnpy.trader.object import BarData
from vnpy.trader.database import DB_TZ, database_manager
ImportError Traceback (most recent call last)
~\AppData\Local\Temp/ipykernel_40572/2917728174.py in <module>
1 from datetime import datetime
2
----> 3 from vnpy.trader.vtConstant import Exchange, Interval
4 from vnpy.trader.object import BarData
5 from vnpy.trader.database import DB_TZ, database_manager
ImportError: cannot import name 'Exchange' from 'vnpy.trader.vtConstant' (e:\ProgramData\Anaconda3\lib\site-packages\vnpy\trader\vtConstant.py)