class_docstr: :class:`BasePreprocessor` to input handle data.
  
  A preprocessor should be used in two steps. First, `fit`, then,
  `transform`. `fit` collects information into `context`, which includes
  everything the preprocessor needs to `transform` together with other
  useful information for later use. `fit` will only change the
  preprocessor's inner state but not the input data. In contrast,
  `transform` returns a modified copy of the input data without changing
  the preprocessor's inner state.
docstr: Fit parameters on input data.
  
  This method is an abstract base method, need to be
  implemented in the child class.
  
  This method is expected to return itself as a callable
  object.
  
  :param data_pack: :class:`Datapack` object to be fitted.
  :param verbose: Verbosity.
docstr_tok: ["Fit","parameters","on","input","data",".","This","method","is","an","abstract","base","method",",","need","to","be","implemented","in","the","child","class",".","This","method","is","expected","to","return","itself","as","a","callable","object",".",":","param","data_pack",":",":","class",":","`","Datapack","`","object","to","be","fitted",".",":","param","verbose",":","Verbosity","."]
code: def fit(
      self, data_pack: "mz.DataPack", verbose: int = 1
  ) -> "BasePreprocessor":
      """
      Fit parameters on input data.
  
      This method is an abstract base method, need to be
      implemented in the child class.
  
      This method is expected to return itself as a callable
      object.
  
      :param data_pack: :class:`Datapack` object to be fitted.
      :param verbose: Verbosity.
      """
  
file_path: MatchZoo/matchzoo/engine/base_preprocessor.py
imports: import abc
  import functools
  import typing
  from pathlib import Path
  import dill
  import matchzoo
label_desc: Use image node_id 3 for calling the BasePreprocessor obj's underlying member method code with example usage: obj.fit(data_pack, verbose) without return types