# List symmetric difference

Python, List · Nov 2, 2020

Returns the symmetric difference between two iterables, without filtering out duplicate values.

- Create a
`set`

from each list. - Use a list comprehension on each of them to only keep values not contained in the previously created set of the other.

```
def symmetric_difference(a, b):
(_a, _b) = (set(a), set(b))
return [item for item in a if item not in _b] + [item for item in b
if item not in _a]
```

`symmetric_difference([1, 2, 3], [1, 2, 4]) # [3, 4]`