html = (
    """<td valign="top">.....</td>        <td width="580" valign="top">.......</td>        <td>.....</td>"""
    )
soup = BeautifulSoup(html)
results = soup.findAll('td', {'valign': 'top'})
for result in results:
    if len(result.attrs) == 1:
        pass
How to find tags with only certain attributes - BeautifulSoup