SwiftCSV
Simple CSV parsing for macOS, iOS, tvOS, and watchOS.
Usage
CSV content can be loaded using the CSV class:
import SwiftCSV
do {
// As a string, guessing the delimiter
let csv: CSV = try CSV(string: "id,name,age\n1,Alice,18")
// Specifying a custom delimiter
let tsv: CSV = try CSV(string: "id\tname\tage\n1\tAlice\t18", delimiter: "\t")
// From a file (propagating error during file loading)
let csvFile: CSV = try CSV(url: URL(fileURLWithPath: "path/to/users.csv"))
// From a file inside the app bundle, with a custom delimiter, errors, and custom encoding.
// Note the result is an optional.
let resource: CSV? = try CSV(
name: "users",
extension: "tsv",
bundle: .main,
delimiter: "\t",
encoding: .utf8)
} catch parseError as CSVParseError {
// Catch errors from parsing invalid CSV
} catch {
// Catch errors from trying to load files
}File Loading
The CSV class comes with initializers that are suited for loading files from URLs.
extension CSV {
/// Load a CSV file from `url`.
///
/// - parameter url: URL of the file (will be passed to `String(contentsOfURL:encoding:)` to load)
/// - parameter delimiter: Character used to separate cells from one another in rows.
/// - parameter encoding: Character encoding to read file (default is `.utf8`)
/// - parameter loadColumns: Whether to populate the columns dictionary (default is `true`)
/// - throws: `CSVParseError` when parsing the contents of `url` fails, or file loading errors.
public convenience init(url: URL,
delimiter: Delimiter,
encoding: String.Encoding = .utf8,
loadColumns: Bool = true) throws
/// Load a CSV file from `url` and guess its delimiter from `CSV.recognizedDelimiters`, falling back to `.comma`.
///
/// - parameter url: URL of the file (will be passed to `String(contentsOfURL:encoding:)` to load)
/// - parameter encoding: Character encoding to read file (default is `.utf8`)
/// - parameter loadColumns: Whether to populate the columns dictionary (default is `true`)
/// - throws: `CSVParseError` when parsing the contents of `url` fails, or file loading errors.
public convenience init(url: URL,
encoding: String.Encoding = .utf8,
loadColumns: Bool = true)
}Delimiters
Delimiters are strongly typed. The recognized CSV.Delimiter cases are: .comma, .semicolon, and .tab.
You can use convenience initializers that guess the delimiter from the recognized list for you. These initializers are available for loading CSV from URLs and strings.
You can also use any other single-character delimiter when loading CSV data. A character literal like "x" will produce CSV.Delimiter.character("x"), so you don't have to type the whole .character(_) case name. There are initializers for each variant that accept explicit delimiter settings.
Reading Data
// Recognized the comma delimiter automatically:
let csv = CSV(string: "id,name,age\n1,Alice,18\n2,Bob,19")
csv.header //=> ["id", "name", "age"]
csv.namedRows //=> [["id": "1", "name": "Alice", "age": "18"], ["id": "2", "name": "Bob", "age": "19"]]
csv.namedColumns //=> ["id": ["1", "2"], "name": ["Alice", "Bob"], "age": ["18", "19"]]The rows can also parsed and passed to a block on the fly, reducing the memory needed to store the whole lot in an array:
// Access each row as an array (array not guaranteed to be equal length to the header)
csv.enumerateAsArray { array in
print(array.first)
}
// Access them as a dictionary
csv.enumerateAsDict { dict in
print(dict["name"])
}Skip Named Column Access for Large Data Sets
By default, the variants of CSV.init will populate its namedColumns and enumeratedColumns to provide access to the CSV data on a column-by-column basis. Think of this like a cross section:
let csv = CSV(string: "id,name,age\n1,Alice,18\n2,Bob,19")
csv.namedRows[0]["name"] //=> "Alice"
csv.namedColumns["name"] //=> ["Alice", "Bob"]If you only want to access your data row-by-row, and not by-column, then you can set the loadColumns argument in any initializer to false. This will prevent the columnar data from being populated.
Skipping this step can increase performance for lots of data.
Installation
CocoaPods
pod "SwiftCSV"Carthage
github "swiftcsv/SwiftCSV"
SwiftPM
.package(url: "https://github.com/swiftcsv/SwiftCSV.git", from: "0.6.1")