I'll throw in sd as a nice sed/find-and-replace tool. Using fd + xargs + sd is a pretty good workflow if a shell glob isn't good enough to target the files you want. https://github.com/chmln/sd
I wanted to like sd but it doesn't support my main use case of recursive search/replace. Imagine if every time you wanted to grep some files you had to build a find -print0 | xargs | rg pipeline... it just takes me out of the flow too much. I'm glad people are posting other options here, I'm looking forward to trying them.
If you haven't discovered recursive path expansion with `**` yet, which is supported by a number of popular shells, including bash, it is about to improve your shell life.
Agreed, doing sd 'search' 'replace' **.py is common in my history. I only mention fd + xargs as a backup for when you need to do something that a simple shell expansion won't cover.
Also, for a "confirm your changes" type workflow, I like git add -p after running the sd command just to review all of the changes.
It's glob and/or bsd_glob from the underlying C stdlib. Another interesting example of things the stdlib glob can do:
#!/usr/bin/perl
# perl since it's an easy way to use an arbitrary function from stdlib
use File::Glob "bsd_glob";
for (bsd_glob("{Hello,Hi} {world,everyone}...a {demo,example}")) {
print($_."\n");
}