1. The most recommended update packages command

pacman -Syu

2. Uninstall a package as completely as possible

pacman -Rns [package name]

• -s to uninstall all dependencies that are no longer required.
• -n to delete all configuation files related to the uninstalled package.

3. Query a installed package

pacman -Qi [package name]

4. Retrieve packages in source databases.

pacman -Ss [key words]

5. Get details of a specific package in the database

pacman -Si [package name]

6. Install python packages for the whole system

pacman -S python-[package name]

7. Unistall all python packages that are not dependent on

pacman -Rns $(pacman -Qdtq | grep '^python-')