.str.split adds leading and trailing empty strings to list result when split by empty string

[knutmerket]

.str.split adds leading and trailing empty strings to list result when split by empty string

[cmdlineluser]

This is fixed on main: #15922

>>> (df.with_columns(fruits_as_charlist=pl.col("fruits").str.split(by="")))
shape: (5, 2)
┌────────┬────────────────────────────────┐
│ fruits ┆ fruits_as_charlist             │
│ ---    ┆ ---                            │
│ str    ┆ list[str]                      │
╞════════╪════════════════════════════════╡
│ apple  ┆ ["a", "p", "p", "l", "e"]      │
│ banana ┆ ["b", "a", "n", "a", "n", "a"] │
│ orange ┆ ["o", "r", "a", "n", "g", "e"] │
│ grape  ┆ ["g", "r", "a", "p", "e"]      │
│ kiwi   ┆ ["k", "i", "w", "i"]           │
└────────┴────────────────────────────────┘