how to cast a i64 Series/chunkedArray into f64 or String in polars-rust?

Question

With a Series which comes from a column of DataFrame, how could cast it into a f64 Series or f64 ChunkedArray? It seems .apply_cast_numeric(|v| v as f64) got failure.

Answer 1

You want to do something like this?

// coerce 'QTY' column from i32 to f32. df is mutable.
df.may_apply(QTY, |s: &Series| s.cast(&DataType::Float32))?;