code: def _build_row(self, row, parent, align, border):
          
          tr = etree.SubElement(parent, 'tr')
          tag = 'td'
          if parent.tag == 'thead':
              tag = 'th'
          cells = self._split_row(row, border)
          # We use align here rather than cells to ensure every row
          # contains the same number of columns.
          for i, a in enumerate(align):
              c = etree.SubElement(tr, tag)
              try:
                  c.text = cells[i].strip()
              except IndexError:
                  c.text = ""
              if a:
                  c.set('align', a)
docs: Given a row of text, build table cells.