polars.Expr.pct_change¶
- Expr.pct_change(n: int = 1) polars.internals.expr.Expr ¶
Percentage change (as fraction) between current element and most-recent non-null element at least n period(s) before the current element.
Computes the change from the previous row by default.
- Parameters
- n
periods to shift for forming percent change.
Examples
>>> df = pl.DataFrame( ... { ... "a": [10, 11, 12, None, 12], ... } ... ) >>> df.with_column(pl.col("a").pct_change().alias("pct_change")) shape: (5, 2) ┌──────┬────────────┐ │ a ┆ pct_change │ │ --- ┆ --- │ │ i64 ┆ f64 │ ╞══════╪════════════╡ │ 10 ┆ null │ ├╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌┤ │ 11 ┆ 0.1 │ ├╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌┤ │ 12 ┆ 0.090909 │ ├╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌┤ │ null ┆ 0.0 │ ├╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌┤ │ 12 ┆ 0.0 │ └──────┴────────────┘