def clean(self):
        tmp_dir = os.path.dirname(self.out_dir)
        d = os.listdir(tmp_dir)
        ok = 0
        if len(d) == 1 and d[0] == 'tvtk_classes':
            ok = 1
        if ok:
            shutil.rmtree(tmp_dir)
        else:
            print("Not removing directory:", tmp_dir)
            print("It does not contain a tvtk_classes directory!")

    #################################################################
    # Non-public interface.
    #################################################################
Returns True if the input consists soley of digits and represents a
dataset/ETHPy150Open enthought/mayavi/tvtk/code_gen.py/TVTKGenerator.clean--crossover with--dataset/ETHPy150Open kenfar/DataGristle/gristle/field_type.py/is_float