Comment by meander_water

The /// script block is actually specified in PEP 723 and supported by several other tools apart from uv.

I’ve started migrating all of my ~15 years of one-off python scripts to have this front matter. Right now, I just update when/if I use them. I keep thinking if were handier with grep/sed/regex etc, I’d try to programmatically update .pys system-wide. But, many aren’t git tracked/version controlled, just laying in whatever dir they service(d). I’ve several times started a “python script dashboard” or “hacky tools coordinator” but stop when I remember most of these are unrelated (to each-other) and un/rarely used. I keep watching the chatter and thinking this is probably an easy task for codex, or some other agent but these pys are “mine” (and I knew^ how they worked when I wrote^ them) and also, they’re scattered and there’s no way I’m turning an agent loose on my file system.

^mostly, some defs might have StackOverflow copy/pasta

This is an awesome features for quick development.

I'm sure the documentation of this featureset highlights what I'm about to say but if you're attracted to the simplicity of writing Python projects who are initialized using this method, do not use this code in staging/prod.

If you don't see why this is not production friendly it's for the simple a good.reaaon that creating deployable artifacts packaging a project or a dependency of a project this uses this method, creating reproducible builds becomes impossible.

This will also lead to builds that pass your CI but fail to run in their destination environment and vice versa due to the fact that they download heir dependencies on the fly.

There may be workarounds and I know nothing of this feature so investigate yourself if you must.

My two cents.

This isn't really "alternatively"; it's pointing out that in addition to the shebang you can add a PEP 723 dependency specification that `uv run` (like pipx, and some other tools) can take into account.

I'm actually a bit annoyed that uv won. I found pdm to be a really nice solution that fixed a lot of the issues poetry had without the hard ideological stance behind it, while fixing most of its problems. But maybe that ideology was partly what drove it's adoption.

Rust is getting this feature too, it's great for one off scripts

Yeah, but you need Nix. If we are reaching out for tools that might not be around, then you can also depend on `curl | sudo bash` to install Nix when not present.

(this is a joke btw)

As shared in a sibling comment, you can get away with just curl+shell: https://paulw.tokyo/standalone-python-script-with-uv/

The issue I have with `nix-shell` is that the evaluation time is long, so if you need to run the script repeatedly it may take a long time. `nix shell` at least fix this issue by caching evaluations, but I think uv is still faster.

This comes with the added benefit that your environment is reverted as soon as you exit the Nix shell.

I just tried the one you are replying to and it worked great on macOS. I frequently use a variant of this on my Mac.