polars.DataTypeExpr.struct.field_names

DataTypeExpr.struct.field_names() → Expr

Get the field names in a struct as a list.

Examples

>>> pl.select(
...     pl.Struct({"x": pl.Int64, "y": pl.String})
...     .to_dtype_expr()
...     .struct.field_names()
... )
shape: (2, 1)
┌─────────┐
│ literal │
│ ---     │
│ str     │
╞═════════╡
│ x       │
│ y       │
└─────────┘