ENH: Styler.to_latex()

I have created a branch adding a to_latex method to Styler.

It is nowhere near readiness, and in particular:

• supports only cell background color as of now - adding some attributes should be trivial, adding others might be less so
• most importantly, it works on a copy of the dataframe casted .astype(str), which is plain wrong because it discards features such as float formatting. For a good result, a better integration is needed with the code that currently does cell formatting in DataFrame.to_latex.

This said, if anyone feels like experimenting, it might be slightly better than starting from scratch.

One aspect which I think is useful, even aside from this branch, and might benefit some discussion, is the pair of methods _latex_preserve and _latex_restore, which basically replace LaTeX commands so that they are not disturbed by escaping, and then restores them. There might be better way to code this, but I really think this is something we need to implement, and to offer to users who happen to nest LaTeX code in their cells.

[MarcoGorelli]

Please, this isn’t helpful - see here for how to contribute, else wait for someone else to do it, but carrying on commenting +1 is disruptive

[moi90]

include \midrule after a specific row

For that, I usually split the generated output into individual lines, insert the extra rules at pre-defined locations and concatenate the result. This breaks easily but it is better than nothing.