I can't do a DELETE in sql python

Question

error during execution 1451 (23000): Cannot delete or update a parent row: a foreign key constraint fails (holamundo.product, CONSTRAINT product_ibfk_1 FOREIGN KEY (create_by) REFERENCES user (id))

I have it in separate .py

       def eliminarCurso(self, codigoCursoEliminar):
       if self.conexion.is_connected():
          try:
             cursor=self.conexion.cursor()
             sql = "delete from user where id = '{0}'"
             cursor.execute(sql.format(codigoCursoEliminar))
             self.conexion.commit()
             print("\n!Curso Eliminado¡\n")
          except Error as ex:
             print("Error : {0}".format(ex))



    elif opcion == 4:
        try:
            cursos = dao.listarCursos()
            if len(cursos) > 0:
               idEliminar = funciones.pedirDatosEliminacion(cursos)
               if not(idEliminar == ""):
                   dao.eliminarCurso(idEliminar)
               else:
                   print("ID de curso no encontrado..\n")
            else:
                print("no se encontro cursos")
        except:
             print("occurio un error")  
    else:
        print("opcion no valida")



    def pedirDatosEliminacion(cursos):
     listarCursos(cursos)

      exiteCodigo = False

      codigoEliminar = int(input("Ingrese el id que quiere eliminar: "))
      for cur in cursos:
          if cur[0] == codigoEliminar:
             exiteCodigo = True
             break
      if not exiteCodigo:
         codigoEliminar = ""
    
      return codigoEliminar