mlrecommender.swift

var users = [Int: UUID]()
var talks = [UUID]()

var csv = ""

for index in 0..<100 {
    users[index] = UUID()
}

for _ in 0..<500 {
    talks.append(UUID())
}

var x = [UUID: UUID]()
var counter = 0
func loop() {
    for (idx, talk) in talks.enumerated() {
        for _ in 0..<Int.random(in: 1..<50) {
            let index = Int.random(in: 0..<100)
            let rating = Int.random(in: 1...9)
            if let talkCache = users[index], talkCache == talk {
                continue
            }
            x[users[index]!] = talk

            csv = csv + "\(counter),\"\(users[index]!)\",\(rating),\"\(talk)\",\(idx)\n"
            counter += 1
        }
    }
}

loop()
print(csv)