我试图在ubuntu 16.04上安装Python 3.7。我在互联网上尝试了安装步骤，但我得到了一个错误代码。
我的安装步骤：

sudo apt update
sudo apt install software-properties-common
sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt update
sudo apt install python3.7

字符串
我的错误：

E: Unable to locate package python3.7
E: Couldn't find any package by glob 'python3.7'
E: Couldn't find any package by regex 'python3.7

型
我尝试了这个方法：

sudo add-apt-repository ppa:deadsnakes/ppa   
sudo apt-get update   
sudo apt install python3.7

型
但我还是犯了同样的错误：

user@ubuntu:~$ sudo apt install python3.7  
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package python3.7
E: Couldn't find any package by glob 'python3.7'
E: Couldn't find any package by regex 'python3.7'

型
我该如何解决这些问题？