sqlalchemy.py

from sqlalchemy import create_engine, Column, Integer, String, ForeignKey
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship, sessionmaker, scoped_session

DBSession = scoped_session(sessionmaker())
Base = declarative_base()        
        
class Words(Base):
    __tablename__ = 'words'
    word = Column(String, primary_key=True)

    def __repr__(self):
        return "<Words('%s')>" % self.word

class Definition(Base):
    __tablename__ = 'definitions'
    id = Column(Integer, primary_key=True)
    word_id = Column(String, ForeignKey('words.word', ondelete='CASCADE', onupdate='CASCADE'))
    part_of_speech = Column(String)
    pronunciation = Column(String)
    definition = Column(String)

    word = relationship('Words', uselist=False, backref='definitions')

    def __repr__(self):
        return "<Definations('%s', '%s', '%s')>" % (self.part_of_speech,
                                                    self.pronunciation,
                                                    self.defination)

if __name__ == '__main__':
    engine = create_engine('sqlite:///lexi.db', echo=True)
    Base.metadata.bind = engine
    Base.metadata.create_all(engine)

    word = Words(word='hello')
    DBSession.add(word)

    d1 = Definition(part_of_speech='pos1',
                    pronunciation='p1',
                    definition='d1',
                    word=word)
    DBSession.add(d1)

    d2 = Definition(part_of_speech='pos2',
                    pronunciation='p2',
                    definition='d2')
    DBSession.add(d2)
    word.definitions.append(d2)

    d3 = Definition(part_of_speech='pos3',
                    pronunciation='p3',
                    definition='d3',
                    word_id=word.word)
    DBSession.add(d3)

    DBSession.commit()