58 lines
1.4 KiB
TypeScript
58 lines
1.4 KiB
TypeScript
import pl, { DataFrame } from 'nodejs-polars'
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import fs, { writeFile } from 'fs'
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export function test_x(params: any) {
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const fooSeries = pl.Series("foo", [1, 2, 3])
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let res = fooSeries.sum()
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console.log(res)
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let df = pl.readCSV("data/iris.csv")
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}
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interface CSVDatabase2 {
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df: DataFrame
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filepath: string
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}
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export function create_csv_database(filepath: string): CSVDatabase2 {
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let df = DataFrame({ 'a_key': ['1'], 'a_value': ['2'] })
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df.writeCSV(filepath)
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return { df, filepath }
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}
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export function save_db(db: CSVDatabase2) {
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db.df.writeCSV(db.filepath)
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}
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export function add_row(db: CSVDatabase2, row: any) {
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let d = DataFrame(row)
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db.df = db.df.vstack(d)
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}
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export function print_head(db: CSVDatabase2) {
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console.log(db.df.head())
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}
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export function delete_row_by_key(db: CSVDatabase2, key: string) {
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console.log("NEXT COLUMNS")
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console.log(db.df.columns)
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db.df = db.df.filter(pl.col('a_key').neq(pl.lit(key)))
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}
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export function select_columns(db: CSVDatabase2, columns: string[]): DataFrame {
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return db.df.select(...columns)
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}
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export function join_dataframes(db1: CSVDatabase2, db2: CSVDatabase2, on: string): DataFrame {
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return db1.df.join(db2.df, { on, how: "inner" }) // or "left", "right", "outer"
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}
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export function add_simple_index(db: CSVDatabase2) {
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const indices = Array.from(Array(db.df.height).keys()) // Create 0-N index
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db.df = db.df.withColumn(pl.Series("index", indices))
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}
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