class_docstr: Helper class for performing BPE subword tokenization.
  
  For technical details, please refer to https://arxiv.org/abs/1508.07909.
  This class just wraps around the official subword-nmt repository.
  
  This API expects the user to call tokenize() (encode) onto the training data,
  then call finalize() to learn the encodings, and then iterate over the data
  in a second pass, calling tokenize() again to get processed output.
class_docstr_tok: ["Helper","class","for","performing","BPE","subword","tokenization",".","For","technical","details",",","please","refer","to","https",":","\/\/arxiv.org\/abs\/1508.07909",".","This","class","just","wraps","around","the","official","subword-nmt","repository",".","This","API","expects","the","user","to","call","tokenize","(",")","(","encode",")","onto","the","training","data",",","then","call","finalize","(",")","to","learn","the","encodings",",","and","then","iterate","over","the","data","in","a","second","pass",",","calling","tokenize","(",")","again","to","get","processed","output","."]
docstr: Copy the codecs file to a new location.
  
  :param target_file:
      where to copy the codecs.
docstr_tok: ["Copy","the","codecs","file","to","a","new","location",".",":","param","target_file",":","where","to","copy","the","codecs","."]
code: def copy_codecs_file(self, target_file: str):
      """
      Copy the codecs file to a new location.
  
      :param target_file:
          where to copy the codecs.
      """
      with PathManager.open(
          target_file, "w", encoding="utf-8"
      ) as wfile:
          with PathManager.open(self.codecs, encoding="utf-8") as rfile:
              for line in rfile:
                  wfile.write(line)
  
imports: from parlai.core.params import ParlaiParser
  from abc import ABC, abstractmethod
  from functools import lru_cache
  import json
  import os
  import random
  import re
  from typing import Dict, List, Optional, Set, Tuple
  from typing_extensions import final
  from parlai.core.build_data import download, make_dir
  from parlai.core.opt import Opt
  from parlai.utils.misc import warn_once
  from parlai.utils.typing import TShared
  from parlai.utils.io import PathManager
  import parlai.utils.logging
label_desc: Use image node_id 7 for calling the SubwordBPEHelper obj's underlying member method code with example usage: obj.copy_codecs_file(target_file) without return types