swift csv

Fast and memory-efficient CSV library in Swift.

84
15
Swift

swift-csv

swift-csv is a stream based CSV library written in Swift. It uses InputStream to parse a CSV file and OutputStream to write CSV data to a file.
This way it doesn’t keep everything in memory while working with big CSV files. It also supports BOM for UTF-8, UTF-16 and UTF-32 text encodings.

swift-csv is battle tested in the CSV import and export of Finances.

Features

  • Stream based CSV parser and writer
  • Complete documentation
  • Unit tested

Usage

Parser

let stream = InputStream(...)

// Define the delimeter and encoding of the CSV file
let configuration = CSV.Configuration(delimiter: ",", encoding: .utf8)

let parser = CSV.Parser(inputStream: stream, configuration: configuration)
try parser.parse()

If you don’t know the delimiter and encoding of the data, you can automatically detect it.

let url = ...
guard let configuration = CSV.Configuration.detectConfigurationForContentsOfURL(url) else {
	return
}

Example

Parsing this CSV file

a,b
1,"ha ""ha"" ha"
3,4

will result in the following delegate calls.

parserDidBeginDocument
parser(_:didBeginLineAt:) 0
parser(_:didReadFieldAt:value:) a
parser(_:didReadFieldAt:value:) b
parser(_:didEndLineAt:) 0
parser(_:didBeginLineAt:) 1
parser(_:didReadFieldAt:value:) 1
parser(_:didReadFieldAt:value:) ha "ha" ha
parser(_:didEndLineAt:) 1
parser(_:didBeginLineAt:) 2
parser(_:didReadFieldAt:value:) 3
parser(_:didReadFieldAt:value:) 4
parser(_:didEndLineAt:) 2
parserDidEndDocument

Writer

let stream = OutputStream(...)
let configuration = CSV.Configuration(delimiter: ",", encoding: .utf8)

let writer = CSV.Writer(outputStream: stream, configuration: configuration)
try writer.writeLine(of: ["a", "b", "c"])
try writer.writeLine(of: ["1", "2", "3"])

The code above produces the following output.

a,b,c
1,2,3

TODOs

  • [ ] Support comments in CSV file

Contact

Matthias Hochgatterer

Github: https://github.com/brutella/

Twitter: https://twitter.com/brutella

License

swift-csv is available under the MIT license. See the LICENSE file for more info.