@std/csv@1.0.4

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Reads and writes comma-separated values (CSV) files.

import { parse } from "@std/csv/parse";
import { assertEquals } from "@std/assert";

const string = "a,b,c\nd,e,f";

assertEquals(parse(string, { skipFirstRow: false }), [["a", "b", "c"], ["d", "e", "f"]]);
assertEquals(parse(string, { skipFirstRow: true }), [{ a: "d", b: "e", c: "f" }]);
assertEquals(parse(string, { columns: ["x", "y", "z"] }), [{ x: "a", y: "b", z: "c" }, { x: "d", y: "e", z: "f" }]);

There are many kinds of CSV files; this module supports the format described in RFC 4180.

A csv file contains zero or more records of one or more fields per record. Each record is separated by the newline character. The final record may optionally be followed by a newline character.

field1,field2,field3

White space is considered part of a field.

Carriage returns before newline characters are silently removed.

Blank lines are ignored. A line with only whitespace characters (excluding the ending newline character) is not considered a blank line.

Fields which start and stop with the quote character " are called quoted-fields. The beginning and ending quote are not part of the field.

The source:

normal string,"quoted-field"

results in the fields

[`normal string`, `quoted-field`]

Within a quoted-field a quote character followed by a second quote character is considered a single quote.

"the ""word"" is true","a ""quoted-field"""

results in

[`the "word" is true`, `a "quoted-field"`]

Newlines and commas may be included in a quoted-field

"Multi-line
field","comma is ,"

results in

[`Multi-line
field`, `comma is ,`]