highlight option not working for python code chunk?

[nietzschetmh]

Hi, i like prettydoc a lot.

I added a python code chunk and R code chunk. It seems the highlight is only working for R code chunk.

Here's the Python code chunk

Here's the R code chunk.

[yixuan]

I feel it is more like a pandoc problem, similar to jgm/pandoc#2054.
You can see that the constants and strings were indeed highlighted, but pandoc didn't emphasize on member functions and keywords like import.

[nietzschetmh]

Thanks yixuan. In that case, i think we could only make ad hoc changes and this is not related to prettydoc.