def get_not_constant_species(model):
    """
    get species of the model that are not constant
    @param model: libsbml.model
    @type model: libsbml.model
    @return: list of species
    @rtype: list[libsbml.species]
    """
    def not_const(s): return not( s.getConstant() or s.getBoundaryCondition() )
    return filter(not_const, model.getListOfSpecies())