解决Some index files failed to download.They have been ignored, or old ones used instead报错

使用sudo apt-get update后报错：

Err:1 http://ppa.launchpad.net/wireshark-dev/stable/ubuntu bionic InRelease
Temporary failure resolving 'ppa.launchpad.net'
Err:2 http://security.ubuntu.com/ubuntu bionic-security InRelease
Temporary failure resolving 'security.ubuntu.com'
Err:3 http://archive.ubuntu.com/ubuntu bionic InRelease
Temporary failure resolving 'archive.ubuntu.com'
Err:4 http://archive.ubuntu.com/ubuntu bionic-updates InRelease
Temporary failure resolving

解决Some index files failed to download.They have been ignored, or old ones used instead报错最先出现在Python成神之路。