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；
docstr: 将 ``batch_field`` 数据 转为 :class:`oneflow.Tensor` 并 pad 到相同长度。
  
  :param batch_field: 输入的某个 field 的 batch 数据。
  :param pad_val: 需要填充的值
  :param dtype: 数据的类型
docstr_tok: ["\u5c06","``","batch_field","``","\u6570\u636e","\u8f6c\u4e3a",":","class",":","`","oneflow.Tensor","`","\u5e76","pad","\u5230\u76f8\u540c\u957f\u5ea6\u3002",":","param","batch_field",":","\u8f93\u5165\u7684\u67d0\u4e2a","field","\u7684","batch","\u6570\u636e\u3002",":","param","pad_val",":","\u9700\u8981\u586b\u5145\u7684\u503c",":","param","dtype",":","\u6570\u636e\u7684\u7c7b\u578b"]
code: def pad(batch_field, pad_val=0, dtype=None):
      """
      将 ``batch_field`` 数据 转为 :class:`oneflow.Tensor` 并 pad 到相同长度。
  
      :param batch_field: 输入的某个 field 的 batch 数据。
      :param pad_val: 需要填充的值
      :param dtype: 数据的类型
      """
      return oneflow.tensor(batch_field, 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 2 for calling the OneflowNumberPadder obj's underlying member method code with example usage: obj.pad(batch_field, pad_val, dtype) and returns: oneflow