code: def process_column(self, idx, value):
          "Process a single column."
          if value is not None:
              value = str(value).decode(self.encoding)
          return valuf process_column(self, idx, value):
          "Process a single column."
          if value is not None:
              value = str(value).decode(self.encoding)
          return value
docs: Process a single column.