규칙에 따라 parsing def solution(new_id): answer = '' for char in new_id: if char.isalpha(): answer += char.lower() elif char == '.' and answer and answer[-1] != '.': answer += '.' elif char.isdigit() or char in '-_': answer += char if not answer: answer += 'a' elif len(answer) > 15: answer = answer[:15] if answer[-1] == '.': answer = answer[:-1] while len(answer) < 3: answer = answer + answer[-1] re..