code: def log_url (self, url_data):
          
          row = []
          if self.has_part("urlname"):
              row.append(url_data.base_url)
          if self.has_part("parentname"):
              row.append(url_data.parent_url)
          if self.has_part("baseref"):
              row.append(url_data.base_ref)
          if self.has_part("result"):
              row.append(url_data.result)
          if self.has_part("warningstring"):
              row.append(self.linesep.join(x[1] for x in url_data.warnings))
          if self.has_part("infostring"):
              row.append(self.linesep.join(url_data.info))
          if self.has_part("valid"):
              row.append(url_data.valid)
          if self.has_part("url"):
              row.append(url_data.url)
          if self.has_part("line"):
              row.append(url_data.line)
          if self.has_part("column"):
              row.append(url_data.column)
          if self.has_part("name"):
              row.append(url_data.name)
          if self.has_part("dltime"):
              row.append(url_data.dltime)
          if self.has_part("dlsize"):
              row.append(url_data.size)
          if self.has_part("checktime"):
              row.append(url_data.checktime)
          if self.has_part("cached"):
              row.append(0)
          if self.has_part("level"):
              row.append(url_data.level)
          if self.has_part("modified"):
              row.append(self.format_modified(url_data.modified))
          self.writerow(map(strformat.unicode_safe, row))
          self.flush()
docs: Write csv formatted url check info.