code: def load_hashes(filename):
      
      # { filename : (sha1 of header if available or 'NA',
      #               sha1 of input,
      #               sha1 of output) }
  
      hashes = {}
      try:
          with open(filename, 'r') as cython_hash_file:
              for hash_record in cython_hash_file:
                  (filename, header_hash,
                   cython_hash, gen_file_hash) = hash_record.split()
                  hashes[filename] = (header_hash, cython_hash, gen_file_hash)
      except (KeyError, ValueError, AttributeError, IOError):
          hashes = {}
      return hashes
docs: Load the hashes dict from the hashfile