class_docstr: MarsDataset that inherit from torch.utils.data.Dataset.
  It converts from Mars basic datatype such as Tensor,
  DataFrame, Series. Additionally, it's constructor can receive
  np.ndarray, pd.DataFrame, pd.Series type.
class_docstr_tok: ["MarsDataset","that","inherit","from","torch.utils.data.Dataset",".","It","converts","from","Mars","basic","datatype","such","as","Tensor",",","DataFrame",",","Series",".","Additionally",",","it","'s","constructor","can","receive","np.ndarray",",","pd.DataFrame",",","pd.Series","type","."]
code: def __getitem__(self, index):
      if not self._executed:
          self._execute()
          self._executed = True
      return tuple(self.get_data(t, index) for t in self._tileables)
  
file_path: mars/mars/learn/contrib/pytorch/dataset.py
imports: import copy
  from typing import List
  import numpy
  import pandas
  from ....None import execute
  from ....core.context import get_context
  from ....tensor.core import TENSOR_TYPE
  from ....dataframe.core import DATAFRAME_TYPE, SERIES_TYPE
  from ....utils import require_not_none
label_desc: Use image node_id 5 for calling the MarsDataset obj's underlying member method code with example usage: obj.__getitem__(index) and returns: tuple