~~~
relevant_domains = [
    'u.smutty.horse',
    'youtu.be',
    'youtube.com',
    'www.youtube.com',
    'm.youtube.com',
    'anonfiles.com', # useless since it's censored
    'catbox.moe',
    'files.catbox.moe',
    'pony.tube',
    'vocaroo.com',
    'voca.ro',
    'clyp.it',
    'instaud.io'
]

CONTENT_URL = re.compile(
        fr'((?:https?://)?(?:{"|".join(relevant_domains)})/[^ \n]*)(?<!\.|,|\))'
)
~~~