def solution(myString):
answer = []
for i in myString.split('x'):
if not i == '':
answer.append(i)
return sorted(answer)
방법 1.
def solution(myString):
answer = ' '.join(myString.split('x')).split()
return sorted(answer)
방법 2.
def solution(myString):
return sorted(ch for ch in myString.split('x') if ch)