code: def write_cache(cache, fobj, format=None):
      
      # open file
      if isinstance(fobj, string_types):
          with open(fobj, 'w') as fobj2:
              return write_cache(cache, fobj2, format=format)
  
      if format is None:
          formatter = str
      elif format.lower() == "lal":
          formatter = _format_entry_lal
      elif format.lower() == "ffl":
          formatter = _format_entry_ffl
      else:
          raise ValueError("Unrecognised cache format {!r}".format(format))
  
      # write file
      for line in map(formatter, cache):
          try:
              print(line, file=fobj)
          except TypeError:  # bytes-mode
              fobj.write("{}\n".format(line).encode("utf-8"))
docs: Write a `list` of cache entries to a file
  
      Parameters
      ----------
      cache : `list` of `str`
          The list of file paths to write
  
      fobj : `file`, `str`
          The open file object, or file path to write to.
  
      format : `str`, optional
          The format to write to, one of
  
          - `None` : format each entry using `str`
          - ``'lal'`` : write a LAL-format cache
          - ``'ffl'`` : write an FFL-format cache