Swiftで日足描画用のCSVファイルを開く ref: https://qiita.com/externvoid@github/items/a2e5bb079b5d208a8bc7

swift2.0.swift

import Foundation
import Darwin
var result: [[String]] = []
let path = "./TEST_Stock.csv"
//let path = "./stest.csv" 
//NSString.stringWithContentsOfFileを呼ぶと、ambigousとか言うので...
do {
  var data = try String(contentsOfFile: path,
                    encoding: NSUTF8StringEncoding)
  data.enumerateLines { (line, stop) -> () in
    result.append(line.componentsSeparatedByString(","))
  }
} catch let e as NSError {print(e.localizedDescription)} 
//print(result)
// taking last 10 elements

let limit = 10
let r: Range<Int> = 0..<result.count-limit
result.removeRange(r)
for (idx, e) in result.enumerate() {
  print("\(idx) : \(e)")
}
var ar: [[Double]] = []
func minmax(result: [[String]], inout ar: [[Double]]) -> (Double, Double) {
//  taking partial part, #1 to #4 of Array -> ArraySlice
  let result0 = result.map( {Array($0[1...4])} )
  ar = result0.map({$0.map({atof($0)})})
  //var max: Double = -1.0, min: Double = Double.infinity//1.0e38
  var max: Double = -Double.infinity, min: Double = -max
  for e in ar {
  // giita:// tag:swift map reduce
    max = e.reduce(max, combine: {$0>$1 ? $0 : $1})
    min = e.reduce(min, combine: {$0<$1 ? $0 : $1})
  }
  return (min, max)
}
let tap = minmax(result, ar: &ar)
print(tap)

swift3.1.swift

let dateFormatter = DateFormatter()
dateFormatter.locale = Locale(identifier: "en_US")

dateFormatter.timeZone = TimeZone(abbreviation: "UTC")
dateFormatter.dateFormat = "yyyy/MM/dd HH:mm:ss Z"
print(dateFormatter.string(from:Date()))

dateFormatter.timeZone = TimeZone(abbreviation: "JST")
print(dateFormatter.string(from:Date()))

dateFormatter.locale = Locale(identifier: "ja_JP")
dateFormatter.dateStyle = .medium
dateFormatter.timeStyle = .full
print(dateFormatter.string(from:Date()))
/* print(TimeZone.abbreviationDictionary) */
/* 2018/12/21 02:03:31 +0000 */                                                 
/* 2018/12/21 11:03:31 +0900 */
/* 2018/12/21 11時03分31秒 日本標準時 */

TEST_Stock.csv