The open-source electronic prototyping platform, for when you want to build something physical. Mostly C++, but can also be coded using PLC languages such as ladder logic.
Both a Linux shell and a command language, Bash makes automating on Linux a breeze.
One of the most commonly-used (TIOBE) and well-liked and most-wanted languages (StackOverflow). Python is incredibly flexible - from web scraping to websites, scripting to media manipulation, Python can do almost anything.