很久不用正則就忘了怎么用了。。趕項目今天還沒空學，找了一個正則網站，還不錯
http://tools.jb51.net/regex/create_reg
swift3.0代碼

private func checkFloatNum(str: String) -> Bool {
        
        // 使用正則表達式一定要加try語句
        do {
            // - 1、創建規則
            let pattern = "[1-9]\\d*.\\d*|0.\\d*[1-9]\\d*"
            // - 2、創建正則表達式對象
            let regex = try NSRegularExpression(pattern: pattern, options: NSRegularExpression.Options.caseInsensitive)
            // - 3、開始匹配
            let res = regex.matches(in: str, options: NSRegularExpression.MatchingOptions(rawValue: 0), range: NSMakeRange(0, str.characters.count))
            // 輸出結果
            guard res.count > 0 else {
                SVProgressHUD.showError(withStatus: "經緯度只能輸入數字")
                return false
            }
            for checkingRes in res {
                print((str as NSString).substring(with: checkingRes.range))
                return true
            }
        }
        catch {
            print(error)
            return false
        }
        return false
    }