Você pode usar collections.Counter
:
from collections import Counter
def solve(lis):
c = Counter(lis)
mx = c.most_common()[0][1]
#or mx = max(c.values())
return [k for k, v in c.items() if v == mx]
print (solve(['a','b','c','b','d','a']))
print (solve(['a','a','b','b','c','c','d']))
print (solve(['a','a','a','b','b','b','c','c','d','d','d'] ))
Resultado:
['a', 'b']
['a', 'c', 'b']
['a', 'b', 'd']
Uma versão ligeiramente diferente do código acima usando itertools.takewhile
:
from collections import Counter
from itertools import takewhile
def solve(lis):
c = Counter(lis)
mx = max(c.values())
return [k for k, v in takewhile(lambda x: x[1]==mx, c.most_common())]