Hm, in my case, I followed a very boring/the right way of doing things,
For example : try getting the book "the Linux programming interface" it s very handy and explains pretty much everything u de want to know about anything in a Linux operation system, it lists and explains the POSIX interface made for you to use in you C code , with example, which surprisingly, u get to find similar interfaces/system calls/library functions that you can use in python to do the same thing.
For regular expressions, watching a small video which explains how they work is definitely more productive, but if you could find some time to spare , try checking how compilers are made, / what constitutes a language (language theory), and automata, it definitely has some math in it , but it s worth it, it gives you an extra mental image , which helps you get a better understanding of where you stand and what you can do. Since apparently regex is also a language, which helps you describe chunks of an other languages and it also has some limitations to be aware of.
For regular expressions, watching a small video which explains how they work is definitely more productive, but if you could find some time to spare , try checking how compilers are made, / what constitutes a language (language theory), and automata, it definitely has some math in it , but it s worth it, it gives you an extra mental image , which helps you get a better understanding of where you stand and what you can do. Since apparently regex is also a language, which helps you describe chunks of an other languages and it also has some limitations to be aware of.