dae han Park wrote:
- are there functions in kwant to draw 2D contour plot of the
Brillouin zone and the band structure along the path of high symmetry points?
The function that you found, kwant.wraparound.plot_2d_bands, is the only "intelligent" band structure plotting routine that exists in Kwant currently.
- If it is not, could I extract data shown from
There’s no way to extract local variables from a Python function call, but you can look at the source code of plot_2d_bands  and use it to your liking. For example, you could simply copy that function into a module of your own, and save the data that you find useful.