code: def encrypt_file(in_path_or_file, out_path_or_file, pk, pk_format=SER_COMPACT,
                   mac_bytes=10, chunk_size=4096, curve=None):
      
      close_in, close_out = False, False
      in_file, out_file = in_path_or_file, out_path_or_file
      try:
          if stringlike(in_path_or_file):
              in_file = open(in_path_or_file, 'rb')
              close_in = True
          if stringlike(out_path_or_file):
              out_file = open(out_path_or_file, 'wb')
              close_out = True
          _encrypt_file(in_file, out_file, pk, pk_format, mac_bytes, chunk_size,
                        curve)
      finally:
          if close_out:
              out_file.close()
          if close_in:
              in_file.close()
docs: Encrypts `in_file' to `out_file' for pubkey `pk'