alright I solved it. double checked the documentation and there is a put_attachment function but it requires a document to be created upfront you will assign the attachment to.
code example just if somebody else needs it:
import couchdb
conn = couchdb.Server('http://localhost:5984')
db = conn['test1']
doc = {'name': 'testfile'}
db.save(doc)
db.put_attachment(doc, data, filename="test.txt.tgz")