polars.Expr.first# Expr.first() → Expr[source]# Get the first value. Examples >>> df = pl.DataFrame({"a": [1, 1, 2]}) >>> df.select(pl.col("a").first()) shape: (1, 1) ┌─────┐ │ a │ │ --- │ │ i64 │ ╞═════╡ │ 1 │ └─────┘