~ is expanded to current user home directory by shell, just like the variable $HOME.

While $HOME is expanded in most places (except inside single quotes), ~ is expanded only in a few specific conditions.

Just want to recommend a very good writeup for bash trap command.

The texlive-fontsextra package is so bloated. It leaves a 1.1 GB package on your file system and pollutes your font cache with thousands of useless fonts.

"|" pipe operator redirects I/O to a subshell.

Variables in a subshell are not visible outside the block of code in the subshell.

It’s common to use c/c++ extension in python program for better performance. But it’s hard to debug c/c++ code when it’s called from python.