text: import sqlalchemy as sa
  from sqlalchemy.ext.declarative import declarative_base
  from sqlalchemy.sql.functions import count
  from sqlalchemy.orm import sessionmaker
  
  conn = sa.create_engine('sqlite:///python_basic/zoo.db')
  
  Base = declarative_base()
  class Zoo(Base):
      __tablename__ = 'zoo'
      critter = sa.Column('critter', sa.String, primary_key=True)
      count = sa.Column('count', sa.Integer)
      damages = sa.Column('damages', sa.Float)
  
      def __init__(self, critter, count, damages) -> None:
          self.critter = critter
          self.count = count
          self.damages = damages
      def __repr__(self):
          return "<zoo({}, {}, {})>".format(self.critter, self.count, self.damages)
  
  Base.metadata.create_all(conn)
  
  
  if __name__ == '__main__':
      first = Zoo('duck', 10, 0.0)
      second = Zoo('bear', 2, 1000.0)
      third = Zoo('weasel', 1, 2000.0)
      print(first)
      Session = sessionmaker(bind=conn)
      session = Session()
      session.add(first)
      session.add_all([second, third])
      session.commit()
  """
      >> cd python_basic
      >> sqlite3 zoo.declarative_base
      >> .tables
      >> select * from zoo;
  """
  
  