How to find tags with only certain attributes - BeautifulSoup

Question

How would I, using BeautifulSoup, search for tags containing ONLY the attributes I search for?

For example, I want to find all

Answer 1

Adding a combination of Chris Redford's and Amr's answer, you can also search for an attribute name with any value with the select command:

from bs4 import BeautifulSoup as Soup
html = '.....\
    .......\
    .....'
soup = Soup(html, 'lxml')
results = soup.select('td[valign]')