Ubuntu14升级到Python3.6

sudo add-apt-repository --remove ppa:jonathonf/python-3.6
sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt update
sudo apt install python3.6

如果报如下错误：

W: GPG error: http://ppa.launchpad.net trusty Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 069ACC7BF5C294DB

解决方法：

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys  069ACC7BF5C294DB