new_data_fileF raises TypeError

Exception stack trace:

File ".../pyCDB/fast_client.py", line 106, in new_data_fileF
  data_file = self.new_data_file(
File "<decorator-gen-15>", line 2, in new_data_file
File ".../pyCDB/pyCDBBase.py", line 348, in _cdb_base_check
  x = func(*args, **kwargs)
File ".../pyCDB/client.py", line 563, in new_data_file
  data_file_id = self.insert("data_files", new_data_file, return_inserted_id=True) #zde je problém
File ".../pyCDB/pyCDBBase.py", line 551, in insert
  values_str = self.mysql_values(fields.values())
File ".../pyCDB/pyCDBBase.py", line 813, in mysql_values
  xxx = ", ".join(map(fn, val_list))
File ".../pyCDB/pyCDBBase.py", line 810, in <lambda>
  fn = lambda val: cls.mysql_str(val, float_format=float_format,
File ".../pyCDB/pyCDBBase.py", line 803, in mysql_str
  res = "'" + res + "'"