Added html board

[rgerkin]

You can display the board in an Ipython notebook with:
from IPython import display

If you have a game running, you can continuously display the moves in one output cell with:

display.display(display.HTML(board.__html__()))

[landscape-bot]

Repository health decreased by 0.04% when pulling 16dc4b0 on rgerkin:master into 417cb51 on niklasf:master.

• 1 new problem was found (including 0 errors and 1 code smell).
• No problems were fixed.

[coveralls]

Coverage decreased (-0.42%) to 90.82% when pulling 16dc4b0 on rgerkin:master into 417cb51 on niklasf:master.

[niklasf]

I am on the fence about this once. Is having an __html__ magic method (with double underscores) a common thing (like __str__ or __unicode__)? Maybe an IPython convention?

[rgerkin]

Are you on the fence about the value of the method, or just the naming convention? I'm happy to have it changed to just html(). I find it useful to watch the games while I interactively code in the IPython notebook, without having to connect to some other GUI frontend.

[niklasf]

Both.

First: Clearly if __html__ is not a widely used convention, we shouldn't mark it as a magic method. So html would be fine.

Then: Something about the CSS and HTML seams so arbitrary to me.

I guess I don't fully appreciate the usefulness because I never used IPython notebooks. Then again having such an html method shouldn't hurt. Do you know some other libraries that provide a similar HTML feature to look at for reference?

[rgerkin]

It's used somewhat frequently in web development libraries, e.g. here. But I'll change it to .html() if that's your vote.

For the arbitrariness of the CSS and HTML, an alternative implementation would be to have a static template (a board.html file in the project) with tags like {{A1}, {{A2}}, and so on, and then the html method would use a template engine (jinja or Mako, or simply string.Template) to substitute the corresponding pieces (their unicode representations) or lack thereof. This keeps content and style separate.

As for the utility of it, it goes beyond an IPython notebook. Any web interface using python-chess as part of the backend will want to have a board rendered in HTML.

[niklasf]

Oh, so __html__ is a thing. I didn't come up with anything useful when searching without the quotes. Let's get the simplest version in and maybe improve on it, later.

Edit: Added some more nitpicking.

[niklasf]

Let's avoid eval.

[rgerkin]

Oops, I fixed this before but it reverted somehow... I think I branched from before the fix. I'll take care of it.

[landscape-bot]

Code quality remained the same when pulling 089cc10 on rgerkin:master into 417cb51 on niklasf:master.

[niklasf]

Thank you! Committed and pushed. I took the liberty to remove the remaining trailing spaces.