我如何找到数字Python的不同数字

Question

I need to find all the distinct digits of a number and put them in an array, without looping.

I have already tried looping, but it is too slow.

If the number was 4884, then I would get [4,8] as an output.

Answer 1

>>> r = set(map(int, str(4884))) 
>>> r
{8, 4}

Answer 2

You can use numpy unique :

num = 4884
res = np.unique(list(str(num))).astype(int)
print(res)

Output:

[4 8]

---

You can also do something like this:

 list(dict(zip(map(int, list(str(num))), [0]*len(str(num)))).keys()) 

Not sure why you would want something so complicated. It is probably not faster than using set .

---

Some tests:

 import timeit >>> timeit.timeit('import numpy as np; np.unique(list(str(4884))).astype(int)', number=10000) 0.1892512352597464 timeit.timeit('set(map(int, str(4884)))', number=10000) 0.02349709570256664 timeit.timeit('map(int, list(dict.fromkeys(list(str(4884)))))', number=10000) 0.02554667675917699 timeit.timeit('list(dict(zip(map(int, list(str(4884))), [0]*len(str(4884)))).keys())', number=10000) 0.03316584026305236 

Using set is definitely the fastest.

Answer 3

use this technique

a = 658556
a = str(a)
mylist = list(dict.fromkeys(list(a)))
print(mylist)

output:

['6', '5', '8']