lst = [1, 2, 4, 5, 6, 2, 5, 2]
used = set()
unique = [x for x in lst if x not in used and (used.add(x) or True)]
print(unique)
from collections import Counter
counter = Counter(lst)
unique = list(counter)
print(unique)
single = [x for x,n in counter.items() if n==1]
print(single)
bHN0ID0gWzEsIDIsIDQsIDUsIDYsIDIsIDUsIDJdCgp1c2VkID0gc2V0KCkKdW5pcXVlID0gW3ggZm9yIHggaW4gbHN0IGlmIHggbm90IGluIHVzZWQgYW5kICh1c2VkLmFkZCh4KSBvciBUcnVlKV0KcHJpbnQodW5pcXVlKQoKZnJvbSBjb2xsZWN0aW9ucyBpbXBvcnQgQ291bnRlcgpjb3VudGVyID0gQ291bnRlcihsc3QpCgp1bmlxdWUgPSBsaXN0KGNvdW50ZXIpCnByaW50KHVuaXF1ZSkKCnNpbmdsZSA9IFt4IGZvciB4LG4gaW4gY291bnRlci5pdGVtcygpIGlmIG49PTFdCnByaW50KHNpbmdsZSk=
[1, 2, 4, 5, 6]
[1, 2, 4, 5, 6]
[1, 4, 6]