code: def drop_table(engine: Engine) -> None:
      """
      Drop all existing table
      """
      Base = declarative_base()
      metadata = MetaData()
      metadata.reflect(bind=engine)
      for key in metadata.tables:
          table = metadata.tables[key]
          if table is not None:
              Base.metadata.drop_all(engine, [table], checkfirst=True)
  
file_path: ColossalAI/applications/ColossalQA/colossalqa/utils.py
imports: import re
  from typing import Union
  from colossalqa.mylogging import get_logger
  from sqlalchemy import Engine, MetaData, create_engine
  from sqlalchemy.exc import SQLAlchemyError
  from sqlalchemy.ext.declarative import declarative_base
label_desc: Use image node_id 1 for calling a global function with example usage: drop_table(engine) without return types