polars.Expr.is_duplicated

Expr.is_duplicated() → Self

Return a boolean mask indicating duplicated values.

Returns:

Expr

Expression of data type Boolean.

Examples

>>> df = pl.DataFrame({"a": [1, 1, 2]})
>>> df.select(pl.col("a").is_duplicated())
shape: (3, 1)
┌───────┐
│ a     │
│ ---   │
│ bool  │
╞═══════╡
│ true  │
│ true  │
│ false │
└───────┘