代表您的评论…我会说windDictionary是Dictionary …
Dictionary denotes in JSON with {} and Array denotes with [] // In printed response you may have array with ()所以，您的天气部分是字典数组…您必须像解析它一样
let weather = mainDictionary["weather"] as! [[String : AnyObject]] // although please not use force unwrap .. either use `if let` or `guard` statement
