Is there an editor that I could install on the Raspbian OS to practice Regex with? If not, what about through Python? If so, is there a good python IDE out there for Raspbian that supports Regexs?
Python itself supports regexes (via a built-in module). If you're just interested in playing around with them, import re in an interactive shell, and you have access to Python's regular expression engine.
Using Regular Expressions on my Raspberry Pi