class_docstr: This class is a data structure to keep the content in the index.json file for sharded checkpoint.
  
  Example:
      >>> index = CheckpointIndexFile.from_file('model.index.json')
      >>> index.append_metadata('model_type', 'bert')
      >>> index.append_weight_map('bert.embeddings.word_embeddings.weight', 'model_0001-of-0002.bin')
      >>> index.export('new_index.json')
class_docstr_tok: ["This","class","is","a","data","structure","to","keep","the","content","in","the","index.json","file","for","sharded","checkpoint",".","Example",":",">",">",">","index","=","CheckpointIndexFile.from_file","(","'model.index.json","'",")",">",">",">","index.append_metadata","(","'model_type","'",",","'bert","'",")",">",">",">","index.append_weight_map","(","'bert.embeddings.word_embeddings.weight","'",",","'model_0001-of-0002.bin","'",")",">",">",">","index.export","(","'new_index.json","'",")"]
docstr: Create a CheckpointIndexFile object from a json file.
  
  Args:
      index_path (str): path to the json file.
  
  Returns:
      CheckpointIndexFile: CheckpointIndexFile object.
docstr_tok: ["Create","a","CheckpointIndexFile","object","from","a","json","file",".","Args",":","index_path","(","str",")",":","path","to","the","json","file",".","Returns",":","CheckpointIndexFile",":","CheckpointIndexFile","object","."]
code: def from_file(index_path: Union[str, Path]):
      """
      Create a CheckpointIndexFile object from a json file.
  
      Args:
          index_path (str): path to the json file.
  
      Returns:
          CheckpointIndexFile: CheckpointIndexFile object.
      """
      index = CheckpointIndexFile()
      index.load(index_path)
      return index
  
file_path: ColossalAI/colossalai/checkpoint_io/index_file.py
imports: import json
  import os
  from collections import OrderedDict
  from pathlib import Path
  from typing import Any, Dict, List, Union
  from .utils import is_dtensor_checkpoint
label_desc: Use image node_id 2 for calling the CheckpointIndexFile obj's underlying member method code with example usage: obj.from_file(index_path) and returns: index