Function polars_core::utils::concat_df

pub fn concat_df<'a, I>(dfs: I) -> PolarsResult<DataFrame>where
    I: IntoIterator<Item = &'a DataFrame>,

Concat the DataFrames to a single DataFrame.

Examples found in repository

src/functions.rs (line 289)

pub fn diag_concat_df(dfs: &[DataFrame]) -> PolarsResult<DataFrame> {
    // TODO! replace with lazy only?
    let upper_bound_width = dfs.iter().map(|df| df.width()).sum();
    let mut column_names = AHashSet::with_capacity(upper_bound_width);
    let mut schema = Vec::with_capacity(upper_bound_width);

    for df in dfs {
        df.get_columns().iter().for_each(|s| {
            let name = s.name();
            if column_names.insert(name) {
                schema.push((name, s.dtype()))
            }
        });
    }

    let dfs = dfs
        .iter()
        .map(|df| {
            let height = df.height();
            let mut columns = Vec::with_capacity(schema.len());

            for (name, dtype) in &schema {
                match df.column(name).ok() {
                    Some(s) => columns.push(s.clone()),
                    None => columns.push(Series::full_null(name, height, dtype)),
                }
            }
            DataFrame::new_no_checks(columns)
        })
        .collect::<Vec<_>>();

    concat_df(&dfs)
}