class_docstr: 可以将形如 ``[1, 2, 3]`` 这类的数据转为 ``oneflow.Tensor([1, 2, 3])``。
  
  :param pad_val: 该值无意义；
  :param ele_dtype: 用于检测当前 field 的元素类型是否可以转换为 :class:`oneflow.Tensor` 类型；
  :param dtype: 输出的数据的 dtype，。如 :class:`oneflow.long`, :class:`oneflow.float32`, :class:`int`, :class:`float` 等；
code: def __init__(self, pad_val=0, ele_dtype=None, dtype=None):
      dtype = _get_dtype(
          ele_dtype, dtype, class_name=self.__class__.__name__
      )
      super().__init__(pad_val=pad_val, dtype=dtype)
  
imports: from inspect import isclass
  import numpy
  from fastNLP.envs.imports import _NEED_IMPORT_ONEFLOW
  from fastNLP.envs.utils import _module_available
  from .padder import Padder
  from .utils import is_number_or_numpy_number, is_number, is_numpy_number_dtype, get_shape, is_numpy_generic_class
  from .exceptions import *
label_desc: Use image node_id 1 to create a new OneflowNumberPadder object from inherited base classes: Padder with example: obj = OneflowNumberPadder(pad_val, ele_dtype, dtype)