BeautifulSoup - How to find a specific class name alone

Question

How to find the li tags with a specific class name but not others? For example:

...
 no wanted 
 not his          


        

Answer 1

You can use CSS selectors to match the exact class name.

html = '''
 no wanted 
 not his one 
 neither this one 
 neither this one 
 neither this one 
 I WANT THIS ONLY ONE
'''

soup = BeautifulSoup(html, 'lxml')

tags = soup.select('li[class="z"]')
print(tags)

The same result can be achieved using lambda:

tags = soup.find_all(lambda tag: tag.name == 'li' and tag.get('class') == ['z'])

Output:

[
 I WANT THIS ONLY ONE
]

---

Have a look at Multi-valued attributes. You'll understand why class_='z' matches all the tags that have z in their class name.

HTML 4 defines a few attributes that can have multiple values. HTML 5 removes a couple of them, but defines a few more. The most common multi-valued attribute is class (that is, a tag can have more than one CSS class). Others include rel, rev, accept-charset, headers, and accesskey. Beautiful Soup presents the value(s) of a multi-valued attribute as a list:

css_soup = BeautifulSoup('
')
css_soup.p['class']
# ["body"]

css_soup = BeautifulSoup('
')
css_soup.p['class']
# ["body", "strikeout"]