class_docstr: Convert between text-label and text-index 
class_docstr_tok: ["Convert","between","text-label","and","text-index"]
code: def __init__(self, character_dict_path=None, use_space_char=False):
      self.beg_str = "sos"
      self.end_str = "eos"
  
      self.character_str = []
      if character_dict_path is None:
          self.character_str = "0123456789abcdefghijklmnopqrstuvwxyz"
          dict_character = list(self.character_str)
      else:
          with open(character_dict_path, "rb") as fin:
              lines = fin.readlines()
              for line in lines:
                  line = line.decode("utf-8").strip("\n").strip("\r\n")
                  self.character_str.append(line)
          if use_space_char:
              self.character_str.append(" ")
          dict_character = list(self.character_str)
  
      dict_character = self.add_special_char(dict_character)
      self.dict = {}
      for i, char in enumerate(dict_character):
          self.dict[char] = i
      self.character = dict_character
  
imports: import numpy
  import paddle
  from paddle.nn import functional
  import re
  from shapely.geometry import Polygon
  import cv2
  import copy
label_desc: Use image node_id 1 to create a new BaseRecLabelDecode object from inherited base classes: object with example: obj = BaseRecLabelDecode(character_dict_path, use_space_char)