sqlalchemy unique in m:m

Question

I scraped a website resulting in a list of dictionaries. [{'name': name of job}, {'skills': [many skills]}, ...] when using sqlalchemy i built the following:

class Job(Base):
    __tablename__ = 'Job'
    # Initialize the Column
    id = Column(Integer, nullable=False, primary_key=True)
    title = Column(String(1000), nullable=False)
    
    # Initialize the relationship
    children = relationship("Job_Skills")

class Job_Skills(Base):
    __tablename__ = 'Job_Skills'
    # Initialize the Column
    id = Column(Integer, nullable=False, primary_key=True)
    job_id = Column(Integer, ForeignKey('Job.id'))
    skill_id = Column(Integer, ForeignKey('Skill.id'))
    # Initialize the relationship
    skill = relationship('Skill')

class Skill(Base):
    __tablename__ = 'Skill'
    # Initialize the Column
    id = Column(Integer, primary_key=True, nullable=False, autoincrement=True)
    name = Column(String(100))

for a_dict in dict_merged:
    # job
    job = Job(title=a_dict["name"]
    session.add(job)
    
    # skills
    job_Skills = Job_Skills()
    session.add(job_Skills)

    # add skill in catalogue
    for my_skill in [x.strip() for x in a_dict["skills"].split(',')]:
        skill = Skill(name=my_skill)
        session.add(skill)

the problem is my skill table has many redundancies, I want it to be a uniqe value catalogue that is connected to the proper job via the Job_Skills table.