pola-rs/polars · error

failed to format duration

Error message

failed to format duration

What it means

Error "failed to format duration" thrown in pola-rs/polars.

Source

Thrown at crates/polars-core/src/chunked_array/temporal/duration.rs:88

        match format {
            "iso" | "iso:strict" => {
                let out: StringChunked =
                    self.phys
                        .apply_nonnull_values_generic(DataType::String, |v: i64| {
                            s.clear();
                            iso_duration_string(&mut s, v, self.time_unit());
                            s.clone()
                        });
                Ok(out)
            },
            "polars" => {
                let out: StringChunked =
                    self.phys
                        .apply_nonnull_values_generic(DataType::String, |v: i64| {
                            s.clear();
                            fmt_duration_string(&mut s, v, self.time_unit())
                                .map_err(|e| polars_err!(ComputeError: "{:?}", e))
                                .expect("failed to format duration");
                            s.clone()
                        });
                Ok(out)
            },
            _ => {
                polars_bail!(
                    InvalidOperation: "format {:?} not supported for Duration type (expected one of 'iso' or 'polars')",
                    format
                )
            },
        }
    }

    /// Construct a new [`DurationChunked`] from an iterator over [`ChronoDuration`].
    pub fn from_duration<I: IntoIterator<Item = ChronoDuration>>(
        name: PlSmallStr,
        v: I,
        tu: TimeUnit,

View on GitHub (pinned to df599052da)

When it happens

Trigger: Thrown at crates/polars-core/src/chunked_array/temporal/duration.rs:88 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of pola-rs/polars@df599052da (2026-08-16). Data as JSON: /api/errors/6b74b0ef843993b6. Report an issue: GitHub.