四个数字无重复的三位数求急

有1234个数字，能组成多少个相同且无重复数字的三位数，并print出每个数

for x in range(1,5):
    for y in range(1,5):
        for z in range(1,5):
            if (x!=y) and (y!=z) and (z!=x):
                print("%d %d %d" % (x, y, z))

combin = []
for i in range(1, 5):
    for j in range(1, 5):
        for k in range(1, 5):
            new = i * 100 + j * 10 + k
            if new not in combin:
                combin.append(new)

for num in combin:
    print(num)

print("共能组成%d个数" % len(combin))

from itertools import permutations

num_lis = ['1', '2', '3', '4']
for i in permutations(num_lis, 3):
    print(''.join(i))