Use red text when printing errors on command line

[brainwane]

A suggested enhancement (from a new user at a sprint night): when twine emits error messages on the command line, print them in red.

[bhrutledge]

I like this idea. Here are some random thoughts.

There was some discussion about caveats in #488 (comment).

Is it worth considering a holistic approach to styling twine's output? Or just keep it simple for now?

I found a couple packages that might help:

• https://pypi.org/project/colorama/
• https://pypi.org/project/colorful/
• https://pypi.org/project/colored/

Could folks share examples of Python command-line tools with well-done colors?

[pradyunsg]

Could folks share examples of Python command-line tools with well-done colors?

pip 😉

https://github.com/pypa/pip/blob/e060970d51c5946beac8447eb95585d83019582d/src/pip/_internal/utils/logging.py#L174

Like, we have a decent setup for colors in logging-to-std-streams -- the other part of actually having output be "gracefully colored" is where pip struggles IMO. :)

packages that might help

I suggest using colorama -- it's a much more battle tested library as per my understanding.

[sigmavirus24]

Isn't colorama problematic to install on Windows?

[pradyunsg]

Isn't colorama problematic to install on Windows?

I don't think so. Windows is the target platform for the main functionality of the library, and it's a pure Python library. (pip vendors and uses it)

Take a look at colorama's PyPI page for more details: https://pypi.org/project/colorama/#description

[sigmavirus24]

I’ve personally only tested it on Windows XP (CMD, Console2), Ubuntu (gnome-terminal, xterm), and OS X.

That doesn't inspire hope. That said, I think I had colorama confused with another project.

We'll also likely want to have a convenient way to determine when to disable colors, including when standard out/error is not a pty/tty. I suspect pip does this already

[bhrutledge]

We'll also likely want to have a convenient way to determine when to disable colors, including when standard out/error is not a pty/tty.

I've been casually bookmarking packages for terminal text styling, and though I don't have a specific example, IIRC some of them have this built-in.

A few more:

• https://pypi.org/project/rich/
• https://pypi.org/project/blessings/
• https://pypi.org/project/crayons/

[sigmavirus24]

I would avoid crayons. It's most likely abandonware

[pradyunsg]

That doesn't inspire hope

Just because it's old doesn't means it's broken. As far as I know, it works pretty well even on Windows 10 systems, and Windows has a reputation related to backward compatibility. ;)

If you're interested in looking at how pip does color handling and all that, the relevant code is pip._internal.utils.logging:ColorizedStreamHandler. Our logging setup colors warnings (yellow) and errors (red) as well as allowing us to dump debug logs to a file, while printing to the std* streams. Feel free to "permanently borrow" any of that code. :)

[pradyunsg]

To be clear, colorama is actively maintained as well. There's been commits on the repo over past few weeks and given that it's pretty broadly used (ala pip), I don't expect twine to bump into any major issues if it switches to using it. :)

[di]

Seems like the decision here is to do this, and to use colorama to do it.