我尝试在 ubuntu 20.04 下安装 pgadmin，阅读文章https://linuxhint.com/best_gui_clients_postgresql_ubuntu/
但经过几次尝试后我收到错误消息：
hoster@hoster-os:~/Downloads$ sudo apt update
E: Malformed entry 1 in list file /etc/apt/sources.list.d/pgdg.list (Suite)
E: The list of sources could not be read.
我检查了下面提到的文件的内容：
hoster@hoster-os:~/Downloads$ cat /etc/apt/sources.list.d/pgdg.list
deb http://apt.postgresql.org/pub/repos/apt/
focal-pgdg main
deb http://apt.postgresql.org/pub/repos/apt/
focal-pgdg main
我有 ：
lsb_release -d; uname -r; uname -i
Description: Ubuntu 20.04.4 LTS
5.15.0-41-generic
x86_64
修复错误和安装 pgadmin 的正确方法是什么？
提前致谢！