def merge(path_from, path_to):
  """ Merges the data from one whisper file into another. Each file must have
  the same archive configuration
"""
  fh_from = open(path_from, 'rb')
  fh_to = open(path_to, 'rb+')
  return file_merge(fh_from, fh_to)
 Merges the data from one whisper file into another. Each file must have
  the same archive configuration

graphite_api/_vendor/whisper.py