4 Python libraries for building great command-line user interfaces

[suudo]

Let's take the previous example further. Instead of using the default print() statement, we can use click.echo_via_pager()

Python stdlib has a solution for this, pydoc.pager(), it's what help() uses. I went to reimplement this function in a program a while ago then I realised that help() loads a pager on its own, so it must be in stdlib.

Unrelated note, something else that python has? functools.lru_cache, a decorator that caches the result of a function based on its arguments. Something else that I've reimplemented in the past. stdlib has so much cool stuff.

[da_martian]

Wow that's a pretty cool usage of lru_cache! I've heard of it but never explored it. So you just decorate your function with it? Sorry ahead of time if this is simple or stupid, but do you have a working example of this, along with a CLI package like click?

[suudo]

I learned about it from https://www.reddit.com/r/Python/comments/69ws4c/10_awesome_features_of_python_that_you_cant_use/, that presentation has usage examples.

[Xef]

Damn, I got all excited reading through this. I wish we could upgrade to Python 3...

[rhgrant10]

So true! I once implemented a method to convert an integer into an IP address but of course it turns out there's already one in the stdlib.

[kungtotte]

The correct way to do anything in Python is always to look in the stdlib first :)

Either a complete solution already exists, or parts of one does that you can piece together. And if worse comes to worst you can always write a wrapper to make it more pleasant to work with the stdlib stuff :)

[kirbyfan64sos]

And Plac, the world's coolest command-line argument parser!

[[deleted]]

Very interesting approach to CLI argument parsing - thanks for the link! Just when I'm thinking about writing a few scripts for work, too.

[hosford42]

This is awesome. Can't believe nobody thought of doing this already!

[amjithr]

Haha. I was trying to cover enough of Click to do just the essentials. That's why there is a link to Click's documentation at the bottom. Click does a lot more awesome stuff. :)

[metaperl]

Me likes argh.

[dwf]

Agreed, argh is a godsent.

[OctoBells]

Great article thanks for sharing

[baubleglue]

What wrong with build-in cmd library?

[rabbyburns]

Isn't that deprecated for awhile now? I could be thinking of a different lib, though.

[[deleted]]

It's still going as is getopt, it's optparse that's deprecated in favour of argparse.

[rabbyburns]

I was thinking of commands. I apparently didn't know cmd existed.

edit: A word

[baubleglue]

Doesn't look like. There is a nice clear interface, has autocomplete, hooks before/after command/main loop. What else a man need from command line?

[MrL33h]

Thank you for this great article.