polars.std#

polars.std(column: str, ddof: int = 1) → Expr[source]#

Get the standard deviation.

This function is syntactic sugar for pl.col(column).std(ddof).

Parameters:

column: Column name.
ddof: “Delta Degrees of Freedom”: the divisor used in the calculation is N - ddof, where N represents the number of elements. By default ddof is 1.

Examples

>>> df = pl.DataFrame(
...     {
...         "a": [1, 8, 3],
...         "b": [4, 5, 2],
...         "c": ["foo", "bar", "foo"],
...     }
... )
>>> df.select(pl.std("a"))
shape: (1, 1)
┌──────────┐
│ a        │
│ ---      │
│ f64      │
╞══════════╡
│ 3.605551 │
└──────────┘
>>> df["a"].std()
3.605551275463989