Swift中的JSON序列化引入了不需要的\ n聊天室

Question

我想知道如何从Swift 3.0中的字典中获取JSON字符串

我当前的实现是在发送到本地服务器（node.JS）时返回不需要的“\ n，：，}和'”字符。这是我的Swift代码

    let params: [String: AnyObject] = [
        "source": result.source.stripeID as AnyObject,
        "amount": amount as AnyObject
    ]
    var request = URLRequest(url:url) 
    request.httpMethod = "POST"
    let params_: [String: AnyObject] = params as [String: AnyObject]
    do {
        request.httpBody = try JSONSerialization.data(withJSONObject: params_, options: .prettyPrinted) // pass dictionary to nsdata object and set it as request body
    } catch let error {
        print(error.localizedDescription)
    }

这是服务器端的输出 { '{\n "amount" : 1000,\n "source" : "card_19a6BqAJHVqwiHrhlHw7Kdvv"\n}': '' }