class_docstr: Base Teacher that extract metadata for dialogues.
class_docstr_tok: ["Base","Teacher","that","extract","metadata","for","dialogues","."]
code: def _load_raw_data(self, data_path):
      print("loading: " + data_path)
  
      if self.datatype.startswith("train"):
          path_to_open = os.path.join(data_path, "train.txt")
      elif self.datatype.startswith("valid"):
          path_to_open = os.path.join(data_path, "valid.txt")
      else:
          path_to_open = os.path.join(data_path, "test.txt")
  
      if self.unseen_task:
          assert self.datatype.startswith("test")
          path_to_open = os.path.join(data_path, "test.txt")
          warn_once("No train/valid splits for unseen tasks")
  
      with PathManager.open(path_to_open) as f:
          raw_data = [json.loads(line.strip()) for line in f]
  
      return raw_data
  
imports: import os
  import copy
  import json
  import random
  from typing import Optional
  from parlai.utils.misc import warn_once
  from parlai.utils.data import DatatypeHelper
  from parlai.core.opt import Opt
  from parlai.core.teachers import DialogTeacher
  from parlai.core.params import ParlaiParser
  from parlai.core.message import Message
  from parlai.utils.io import PathManager
  from parlai.tasks.wizard_of_internet import constants
  from .mutators import normalize_reply, get_knowledge_appended_context, get_knowledge_sentence_with_special_tokens_only
  from .build import build
  from .constants import FeedbackType, TITLE_PASSAGE_DELIMITER, OK_LABEL, NOT_OK_LABEL
label_desc: Use image node_id 3 for calling the FitsBaseTeacher obj's underlying member method code with example usage: obj._load_raw_data(data_path) and returns: raw_data