qrep is a command line tool for search-and-replace. It's kind of like sed, but indecisive -- it won't replace anything until you tell it to.
You invoke it like this:
qrep term replacement file.txt
It will search through file.txt looking for term. When it finds a match, it will ask you if you want to replace term with replacement, highlighting them with fancy magical terminal escape codes. If you say yes, it will make the replacement.
It looks like this: 
term is interpreted as a Python regular expression, directly. In replacement, capture groups from the regex are available using backslash notation. So for example,
qrep 'def ([a-z]+)(\(.*\)):' 'def \2\1:' qrep.py
will switch the name and arguments of each function definition in the file qrep.py.
If the file argument is a directory and you specify -r or --recursive, qrep will recursively perform the search through each file and subdirectory. You can exclude files or subdirectories by pattern with the --ignore flag:
qrep -r --ignore node_modules myVar myRenamedVar .
Install from PyPI via pip:
pip install qrep