Struct SchemaSummary 

pub struct SchemaSummary {
    pub rows: usize,
    pub columns: usize,
    /* private fields */
}

A small, displayable description of a Table’s columns.

Fields

rows: usize

Number of data rows.

columns: usize

Number of columns.

Implementations

impl SchemaSummary

pub fn column_summaries(&self) -> &[ColumnSummary]

Per-column summaries, in column order.

Examples found in repository

examples/data_01_schema_summary.rs (line 39)

fn main() -> Result<(), matten_data::MattenDataError> {
    let csv = "\
region,sales,cost,active
north,100,40.5,true
south,150,,true
east,120,55.0,false";

    let table = Table::from_csv_str(csv)?;

    // Top-level shape of the table.
    println!("rows    : {}", table.row_count());
    println!("columns : {}", table.column_count());
    println!("names   : {:?}", table.column_names());

    // A printable, one-glance summary (Table: R rows x C columns, then a line
    // per column with its inferred kind and missing count).
    let summary = table.schema_summary();
    print!("{summary}");

    // The same information, per column, if you want to act on it in code.
    println!("--- per-column ---");
    for col in summary.column_summaries() {
        println!(
            "{:<8} kind={:<7} missing={}",
            col.name, col.kind, col.missing
        );
    }

    // The "cost" column has exactly one missing cell (south).
    let cost = summary
        .column_summaries()
        .iter()
        .find(|c| c.name == "cost")
        .expect("cost column exists");
    assert_eq!(cost.missing, 1);
    assert_eq!(table.row_count(), 3);
    assert_eq!(table.column_count(), 4);

    println!("data_01_schema_summary: OK");
    Ok(())
}

Trait Implementations

impl Clone for SchemaSummary

fn clone(&self) -> SchemaSummary

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SchemaSummary

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for SchemaSummary

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.