代碼如下:
import time, random

class GuessNum:
    def __init__(self):
        self._num = ''
        self.input_num = []
        self.count = 1                                      #猜對所用次數
        self.sec = 0                                           #猜對所用時間
        self._generate_num()

    def _generate_num(self):                        #產生不重復的四個數字
        seq_zton = list(range(10))
        for i in range(0, 4):
            a = str(random.choice(seq_zton))   #選出一個數字
            self._num += a
            seq_zton.remove(int(a))                 #注意a的類型

        self.sec = time.clock()                          #開始計時

    def check_answer(self):
        return self._num

    def check_input(self):
        num_pos, num_value = 0, 0               #位置對和數值對的分別的個數
        tmp = input("Please input the number you guess(No repetition),or 'c' to check the answer:")
        if tmp == 'c':
            print(self.check_answer())
            tof = self.check_input()
            return tof
        elif not tmp.isalnum or not len(tmp) == 4:
            print("Wrong format!")
            tof = self.check_input()                #需要優化