code: def write(self, attr_name, prefix=None):
          '''Write attribute's value to a file.
  
          :param str attr_name:
              Attribute's name to be logged
  
          :param str prefix:
              Optional. Attribute's name that is prefixed to logging message,
              defaults to ``None``.
  
          :returns: message written to file
          :rtype: str
          '''
          if self._folder is None:
              return
  
          separator = "\t"
          attr = getattr(self.obj, attr_name)
          if hasattr(attr, '__iter__'):
              msg = separator.join([str(e) for e in attr])
          else:
              msg = str(attr)
  
          if prefix is not None:
              msg = "{}\t{}".format(getattr(self.obj, prefix), msg)
  
          path = self.get_file(attr_name)
          with open(path, 'a') as f:
              f.write("{}\n".format(msg))
  
          return msf write(self, attr_name, prefix=None):
          '''Write attribute's value to a file.
  
          :param str attr_name:
              Attribute's name to be logged
  
          :param str prefix:
              Optional. Attribute's name that is prefixed to logging message,
              defaults to ``None``.
  
          :returns: message written to file
          :rtype: str
          '''
          if self._folder is None:
              return
  
          separator = "\t"
          attr = getattr(self.obj, attr_name)
          if hasattr(attr, '__iter__'):
              msg = separator.join([str(e) for e in attr])
          else:
              msg = str(attr)
  
          if prefix is not None:
              msg = "{}\t{}".format(getattr(self.obj, prefix), msg)
  
          path = self.get_file(attr_name)
          with open(path, 'a') as f:
              f.write("{}\n".format(msg))
  
          return msg
docs: Write attribute's value to a file.
  
          :param str attr_name:
              Attribute's name to be logged
  
          :param str prefix:
              Optional. Attribute's name that is prefixed to logging message,
              defaults to ``None``.
  
          :returns: message written to file
          :rtype: str