Leer una cadena de caracteres e imprimir las dos palabras que más veces se repite

def word_count(string):
  word_list = string.split(' ')
  word_count = {}
  for w in word_list:
    if w in word_count:
      word_count[w] += 1
    else:
      word_count[w] = 1
  max_count = 0
  for k, v in word_count.items():
      if v > max_count:
         max_count = v
  print_list = []
  for k, v in word_count.items():
      if v == max_count:
         print_list.append(k)
  print(print_list)

word_count("Hello world world hello hello")