code: def dump_frames(group, directory, extension, separator):
      r"""Save a group of data frames to disk.
  
      Parameters
      ----------
      group : alphapy.Group
          The collection of frames to be saved to the file system.
      directory : str
          Full directory specification.
      extension : str
          File name extension, e.g., ``csv``.
      separator : str
          The delimiter between fields in the file.
  
      Returns
      -------
      None : None
  
      """
      logger.info("Dumping frames from %s", directory)
      gnames = [item.lower() for item in group.members]
      gspace = group.space
      for gn in gnames:
          fname = frame_name(gn, gspace)
          if fname in Frame.frames:
              logger.info("Writing Data Frame for %s", fname)
              df = Frame.frames[fname].df
              write_frame(
                  df, directory, fname, extension, separator, index=True
              )
          else:
              logger.info("Data Frame for %s not found", fname)
  
file_path: AlphaPy/alphapy/frame.py
imports: from alphapy.globals import PSEP, SSEP, USEP
  from alphapy.globals import TAG_ID
  import logging
  import pandas
label_desc: Use image node_id 5 for calling a global function with example usage: dump_frames(group, directory, extension, separator) without return types