code: def _process_input(x):
      from .initializer import DataFrame, Series
  
      if isinstance(
          x, (DATAFRAME_TYPE, SERIES_TYPE)
      ) or pd.api.types.is_scalar(x):
          return x
      elif isinstance(x, pd.Series):
          return Series(x)
      elif isinstance(x, pd.DataFrame):
          return DataFrame(x)
      elif isinstance(x, (list, tuple, np.ndarray, TENSOR_TYPE)):
          return astensor(x)
      raise NotImplementedError
  
imports: from collections import OrderedDict
  from functools import reduce
  import numpy
  import pandas
  from ..core import FuseChunkData, FuseChunk, ENTITY_TYPE, OutputType
  from ..core.operand import Operand, TileableOperandMixin, Fuse, ShuffleProxy, FuseChunkMixin
  from ..tensor.core import TENSOR_TYPE
  from ..tensor.datasource import tensor
  from ..tensor.operands import TensorOperandMixin
  from ..utils import calc_nsplits
  from .core import DATAFRAME_CHUNK_TYPE, SERIES_CHUNK_TYPE, INDEX_CHUNK_TYPE, DATAFRAME_TYPE, SERIES_TYPE, INDEX_TYPE, DATAFRAME_GROUPBY_TYPE, SERIES_GROUPBY_TYPE, CATEGORICAL_TYPE
  from .utils import parse_index
label_desc: Use image node_id 19 for calling the DataFrameOperandMixin obj's underlying member method code with example usage: obj._process_input(x) and returns: x, Series, DataFrame, astensor