How can I check the background color of the terminal?

[Zac-HD]

I'm using Rich to highlight output from the Hypothesis ghostwriter (code), but unfortunately the monokai theme is unreadable on light-background terminals. Is there any way to tell whether the terminal background color is light or dark, so that I can use monokai_light or monokai themes respectively?

Setting a background color leaves many trailing spaces when the output is piped into a file, as well as being less pretty (see #990). The ansi_light or ansi_dark themes are readable (#284) but relatively ugly.

[willmcgugan]

There is no standard way to detect the terminal background. There are a few ways that work on some terminals, but on most terminals it is impossible AFAIK.

If you want the highlighting to blend with the user's color theme your only option is to use an ansi_* theme. Alternatively you could expose the theme via a env var or setting.

[Zac-HD]

Darn. In the interests of simplicity I might just recommend that light-theme users run NO_COLOR=1 hypothesis write ... instead 😕

[willmcgugan]

If you like, but it would be easy enough to implement something like LIGHT_BACKGROUND=1 hypothesis write.

syntax = Syntax(code, theme="fruity" if "LIGHT_BACKGROUND" in os.environ else "monokai")

[Zac-HD]

I ended up going with the existing DJANGO_COLORS and COLORFGBG environment variables.

[erezsh]

Perhaps it's worth implementing something like this for rich? https://github.com/dalance/termbg

I think this issue is going to be quite common.