I get this error when creating a BoundMetaData object in SQLAlchemy 0.3.10. The fix is to just use MetaData instead of BoundMetaData. BoundMetaData is deprecated and replaced with MetaData
Example code:
from sqlalchemy import *
db = create_engine('sqlite:///test.db')
metadata = MetaData(db)
"""
Continue with the rest of your Python code
"""
