[simonw]

This works really well in my experience, but it does mean you need to have a working internet connection the first time you run the script.

  # /// script
  # dependencies = [
  #     "cowsay",
  # ]
  # ///
  import cowsay
  cowsay.cow("Hello World")

Then:

  uv run cowscript.py

It manages a disposable hidden virtual environment automatically, via a very fast symlink-based caching mechanism.

You can also add a shebang line so you can execute it directly:

  #!/usr/bin/env -S uv run --script
  #
  # /// script
  # dependencies = ["cowsay"]
  # ///
  import cowsay
  cowsay.cow("Hello World")

Then:

  chmod 755 cowscript
  ./cowscript

[vovavili]

If not having a working internet connection is a concern, I would package your script into a shiv zipapp - https://shiv.readthedocs.io/en/latest/

[emidln]

I wish env -S was more portable. It's a newer feature of the coreutils env implementation and isn't supported elsewhere afaik.

[networked]

You can use so-called "exec magic" instead of `env -S`. Here is an explanation with Python examples: https://dbohdan.com/scripts-with-dependencies#exec-magic (disclosure: my site). In short:

  #! /bin/sh
  "exec" "/usr/bin/env" "uv" "run" "--quiet" "--script" "$0" "$@"
  # /// script
  # dependencies = [
  #   "cowsay",
  # ]
  # ///
  import cowsay
  cowsay.cow("Hello, world!")

On systems that can't run uv, like NetBSD and OpenBSD, switch to pipx:

  #! /bin/sh
  "exec" "/usr/bin/env" "pipx" "run" "$0" "$@"
  # ...

[collinfunk]

FreeBSD 6.0 added 'env -S'. They have adopted a few different GNU inspired options recently, which I am happy about.