Error committing multiple items to one table in SQLite DB model with flask-sqlalchemy

...
# Passed variables to DB
new_professor = Professors(
    name=name,
    hindex=hindex_int)

db.session.add(new_professor)
db.session.commit()
return redirect("/registrants")

professorA = Professors(
    name=nameA,
    hindex=hindex_intA)

professorB = Professors(
    name=nameB,
    hindex=hindex_intB)

db.session.add(professorA)
db.session.add(professorB)
db.session.commit()
return redirect("/registrants")