polars.Expr.str.lengths

Expr.str.lengths() → Expr

Get length of the strings as UInt32 (as number of bytes).

Notes

The returned lengths are equal to the number of bytes in the UTF8 string. If you need the length in terms of the number of characters, use n_chars instead.

Examples

>>> df = pl.DataFrame({"s": ["Café", None, "345", "東京"]}).with_columns(
...     [
...         pl.col("s").str.lengths().alias("length"),
...         pl.col("s").str.n_chars().alias("nchars"),
...     ]
... )
>>> df
shape: (4, 3)
┌──────┬────────┬────────┐
│ s    ┆ length ┆ nchars │
│ ---  ┆ ---    ┆ ---    │
│ str  ┆ u32    ┆ u32    │
╞══════╪════════╪════════╡
│ Café ┆ 5      ┆ 4      │
│ null ┆ null   ┆ null   │
│ 345  ┆ 3      ┆ 3      │
│ 東京  ┆ 6      ┆ 2      │
└──────┴────────┴────────┘