You can feed an iterable such as dict.values to collections.Counter:
from collections import Counter
votes = {"user1": "yes", "user2": "no", "user3": "yes",
"user4": "no", "user5": "maybe", "user6": "yes"}
res = Counter(votes.values())
print(res)
Counter({'yes': 3, 'no': 2, 'maybe': 1})
