code: def scalar_readers(root_path):
      """Returns an iterator that yields (dir, digest, reader) tuples.
  
      For each yielded events dir, `digest` changes whenever events have
      been written to the dir.
  
      `reader` is an instance of ScalarReader that can be used to read
      scalars in dir.
      """
      _ensure_tb_logging_patched()
      for subdir_path in _tfevent_subdirs(root_path):
          digest = _event_files_digest(subdir_path)
          yield subdir_path, digest, ScalarReader(subdir_path)
  
imports: import glob
  import hashlib
  import logging
  import os
  from guild import tensorboard_util
label_desc: Use image node_id 5 for calling a global function with example usage: scalar_readers(root_path) without return types