def _format_line(self,side,flag,linenum,text):
        """Returns HTML markup of "from" / "to" text lines

        side -- 0 or 1 indicating "from" or "to" text
        flag -- indicates if difference on line
        linenum -- line number (used for line number column)
        text -- line text to be marked up
        """
        try:
            linenum = '%d' % linenum
            id = ' id="%s%s"' % (self._prefix[side],linenum)
        except TypeError:
            # handle blank lines where linenum is '>' or ''
            id = ''
        # replace those things that would get confused with HTML symbols
        text=text.replace("&","&amp;").replace(">","&gt;").replace("<","&lt;")

        # make space non-breakable so they don't get compressed or line wrapped
        text = text.replace(' ','&nbsp;').rstrip()

        return '<td class="diff_header"%s>%s</td><td nowrap="nowrap">%s</td>' \
               % (id,linenum,text)
dataset/ETHPy150Open babble/babble/include/jython/Lib/difflib.py/HtmlDiff._format_line/original