code: def set_path(self, file_path):
          
          if not file_path:
              self.read_data = self.memory_read
              self.write_data = self.memory_write
          elif not is_valid(file_path):
              self.write_data(file_path, {})
  
          self.path = file_path
docs: Set the path of the database.
          Create the file if it does not exist.