class_docstr: Class for loading text data with batches 
class_docstr_tok: ["Class","for","loading","text","data","with","batches"]
code: def extract(self, export: bool = True):
      self._extract_files_paths()
  
      content_list = []
      for file_path in self.meta_df["file_path"].tolist():
          with open(file_path, "r") as text_file:
              content = text_file.read()
              content_list.append(content)
  
      new_column = pd.Series(
          data=content_list, index=self.meta_df.index
      )
  
      self.meta_df.insert(
          loc=self.meta_df.columns.get_loc("file_path"),
          column="text",
          value=new_column,
      )
      self.meta_df = self.meta_df.drop(["file_path"], axis=1)
  
      if export:
          self.export_to_csv()
  
      return self.meta_df
  
imports: import glob
  import json
  import os
  from abc import ABC, abstractmethod
  import pandas
label_desc: Use image node_id 2 for calling the TextBatchLoader obj's underlying member method code with example usage: obj.extract(export) and returns: self