我想知道什么是最好的方法来获取包含以下格式行的文本文件：姓：名：猫的数量：狗的数量：鱼的数量：其他宠物的数量
并生成包含以下格式行的文本文件：

名字姓氏：宠物总数

例如，它将使用包含以下内容的文本文件：

Apple:Tim:0:0:3:0
Jobs:Steve:0:0:5:2
Da Kid:Billie:0:1:0:1
White:Walter:2:1:1:0
Bond:James:2:2:3:0
Stark:Tony:0:1:2:0
Wayne:Bruce:0:0:0:0

并输出一个文本文件，如下所示：

Tim Apple:3
Steve Jobs:7
Bille Da Kid:2
Walter White:4
James Bond:7
Tony Stark:3
Bruce Wayne:0

以下是我一直在尝试但没有成功的方法：

let namesFile = "Names"
let dir = try? FileManager.default.url(for: .documentDirectory,
      in: .userDomainMask, appropriateFor: nil, create: true)

// If the directory was found, we write a file to it and read it back
if let fileURL = dir?.appendingPathComponent(namesFile).appendingPathExtension("txt") {
    print (fileURL)

    var petSum = 0;
    do {
        let entriesString = try String(contentsOf: fileURL)

        let entries = entriesString.components(separatedBy: "\n")

        for entry in entries {
            let namePets = entry.components(separatedBy: ":")

            if (namePets.indices.contains(1)) {
                var sum = 0;

                print(namePets[1])
                print(namePets[0])

                for namePet in namePets {
                    if let intArg = Int(namePet) {
                        sum = sum + intArg
                    }
                }
                print (sum)
                print ("\n")
            }
        }

    } catch {
        print("Failed reading from URL, Error: " + error.localizedDescription)
    }
}
else {
    print("didn't work")
}

/*
 // Read from the file
 var inString = ""
 // Write to the file named Test
 let outString = "Write this text to the file"
 do {
     try outString.write(to: fileURL, atomically: true, encoding: .utf8)
 } catch {
     print("Failed writing to URL: \(fileURL), Error: " + error.localizedDescription)
 }

 */

会很感激任何帮助，谢谢！