Anything that already exists in my shell's history as a one-liner, but needs to be upgraded to a reusable script.

As far as I know, one liners are not possible in Python. As a matter of fact, I'm not aware of any popular tools that can even hold a candle to Perl's power at the command line. So, my options are:

1. Forget about one-liners. This is the option most people seem to take, and also by far the worst one. In my career I regularly saw my perfectly competent colleagues take minutes or hours to write throwaway scripts to do what I would do in seconds with a Perl one-liner.

2. Use Perl for one-liners, then rewrite the few that graduate to scripts in Python. This one isn't as obviously absurd as the first, but still seems like a rather large waste of time overall.

3. The obvious: paste your one-liner into a new file, add some newlines and whitespace and command-line options and whatever else.

That makes sense!

When I write one liners I tend to build them up in bash, and so when I want them to be reusable I do the same as your (3) but targeting bash. Then when they get at all complicated I rewrite in python.

The thing about bash is that it's much less powerful than perl, while at the same time being more prone to surprising, undesirable behavior and write-only code.

The worst of both worlds.

I agree that bash has a lot of flaws, but on the other hand it makes a much better shell than perl. I really value using the same language for ordinary interaction with my computer and automation of very simple tasks.