code: def to_dict_str(origin_value, encode=None):
      
      value = copy.deepcopy(origin_value)
      for k, v in value.items():
          if isinstance(v, dict):
              value[k] = to_dict_str(v, encode)
              continue
  
          if isinstance(v, list):
              value[k] = to_list_str(v, encode)
              continue
  
          if encode:
              value[k] = encode(v)
          else:
              value[k] = default_encode(v)
  
      return value
docs: recursively convert dict content into string