docstr: Numerical variable store backed by HDF5.
  
  If `archive` is specified, then `root_path` refers to the filename
  inside the archive.
  
  If `archive` is not specified, then `root_path` refers to the path of
  the h5 file on disk.
docstr_tok: ["Numerical","variable","store","backed","by","HDF5",".","If","`","archive","`","is","specified",",","then","`","root_path","`","refers","to","the","filename","inside","the","archive",".","If","`","archive","`","is","not","specified",",","then","`","root_path","`","refers","to","the","path","of","the","h5","file","on","disk","."]
code: def __init__(self, root_path, archive=None, mode="r"):
      """Numerical variable store backed by HDF5.
  
      If `archive` is specified, then `root_path` refers to the filename
      inside the archive.
  
      If `archive` is not specified, then `root_path` refers to the path of
      the h5 file on disk.
      """
      self.root_path = root_path
      self.mode = mode
      self.archive = archive
      self.io_file = None
  
      if self.archive:
          if self.mode == "w":
              self.io_file = io.BytesIO()
          else:
              self.io_file = self.archive.open(self.root_path, "r")
          self.h5_file = h5py.File(self.io_file, mode=self.mode)
      else:
          self.h5_file = h5py.File(root_path, mode=self.mode)
  
imports: import datetime
  import io
  import json
  import tempfile
  import warnings
  import zipfile
  import numpy
  from keras.backend.common import global_state
  from keras.layers.layer import Layer
  from keras.losses.loss import Loss
  from keras.metrics.metric import Metric
  from keras.optimizers.optimizer import Optimizer
  from keras.saving.serialization_lib import ObjectSharingScope
  from keras.saving.serialization_lib import deserialize_keras_object
  from keras.saving.serialization_lib import serialize_keras_object
  from keras.trainers.compile_utils import CompileMetrics
  from keras.utils import file_utils
  from keras.utils import naming
  from keras.version import __version__
label_desc: Use image node_id 1 to create a new H5IOStore object  with example: obj = H5IOStore(root_path, archive, mode)