用python把1 2 3 4 四個數字，組合成互不相同且無重複數字的3位數

def count_num():
    count = 0
    for i in range(1, 5):
        for j in range(1, 5):
            for k in range(1, 5):
                if (i != k) and (i != j) and (j != k):
                    print(i, j, k)
                    count += 1
    print('一共有{}個互不相同且無重複數字的3位數'.format(count))