check if all the digits of the given number are different

I want to create a 4-digit number between 1000 and 10000 with different digits, but I am a bit inexperienced as I am new to this stuff. Can you help me?

import random

number = random.choice(range(1000,10000))


print(number)

>Solution :

import random

a = 0
while a == 0:
    a, b, c, d = random.sample(range(10), 4)
k = 1000*a + 100*b + 10*c + d
print(k)