polars.Expr.sign

Expr.sign() → Self

Compute the element-wise indication of the sign.

The returned values can be -1, 0, or 1:

• -1 if x < 0.

• 0 if x == 0.

• 1 if x > 0.

(null values are preserved as-is).

Examples

>>> df = pl.DataFrame({"a": [-9.0, -0.0, 0.0, 4.0, None]})
>>> df.select(pl.col("a").sign())
shape: (5, 1)
┌──────┐
│ a    │
│ ---  │
│ i64  │
╞══════╡
│ -1   │
│ 0    │
│ 0    │
│ 1    │
│ null │
└──────┘