---
title: all_unique
tags: list,beginner
---

Returns `True` if all the values in a flat list are unique, `False` otherwise.

Use `set()` on the given list to remove duplicates, compare its length with the length of the list.

```py
def all_unique(lst):
  return len(lst) == len(set(lst))
```

```py
x = [1,2,3,4,5,6]
y = [1,2,2,3,4,5]
all_unique(x) # True
all_unique(y) # False
```