# polars.Expr.list.set_difference#

Expr.list.set_difference(other: IntoExpr) Expr[source]#

Compute the SET DIFFERENCE between the elements in this list and the elements of `other`.

Parameters:
other

Right hand side of the set operation.

`polars.Expr.list.diff`

Calculates the n-th discrete difference of every sublist.

Examples

```>>> df = pl.DataFrame(
...     {
...         "a": [[1, 2, 3], [], [None, 3], [5, 6, 7]],
...         "b": [[2, 3, 4], [3], [3, 4, None], [6, 8]],
...     }
... )
>>> df.with_columns(pl.col("a").list.set_difference("b").alias("difference"))
shape: (4, 3)
┌───────────┬──────────────┬────────────┐
│ a         ┆ b            ┆ difference │
│ ---       ┆ ---          ┆ ---        │
│ list[i64] ┆ list[i64]    ┆ list[i64]  │
╞═══════════╪══════════════╪════════════╡
│ [1, 2, 3] ┆ [2, 3, 4]    ┆ [1]        │
│ []        ┆ [3]          ┆ []         │
│ [null, 3] ┆ [3, 4, null] ┆ []         │
│ [5, 6, 7] ┆ [6, 8]       ┆ [5, 7]     │
└───────────┴──────────────┴────────────┘
```