@zhimsel sorry not giving a feedback before.

I've tested over here in a clean environment, and I was not able to reproduce the behavior you described. I mean, I've tested with only python-mode and vim-colorschemes plugins and the highlight worked as expected.

Are you sure that there isn't any other plugins/configs interacting in your environment? Which theme are you using? solarized-dark?

Are you sure that there isn't any other plugins/configs interacting in your environment?

It's quite possible. I can do some reductive testing to see if any other plugins are interfering when I get the time. I'll report back here once I've had the chance.

Which theme are you using? solarized-dark?

Yes, solarized-dark.

Thanks @zhimsel !
I'm using a docker-environment to test python-mode. You can give it a try to start from a cleaner env without messing up with your own.
You can find more info about it here:
#977

@diraol I was able to do some more verification of this issue.

Using the following vimrc with neovim 0.3.4:

source ~/.vim/vim-plug/plug.vim  " managed externally
call plug#begin('~/.vim/plugins')
  Plug 'altercation/vim-colors-solarized'
  Plug '~/dev/python-mode',
call plug#end()

" Set color scheme
silent! colorscheme solarized

set cursorline " Highlight current line
syntax enable " Enable syntax highlighting

" show highlight group for what's under the cursor
map <F10> :echo "hi<" . synIDattr(synID(line("."),col("."),1),"name") . '> trans<'
\ . synIDattr(synID(line("."),col("."),0),"name") . "> lo<"
\ . synIDattr(synIDtrans(synID(line("."),col("."),1)),"name") . ">"<CR>

I confirmed that the . is de-highlighted in the current line with cursorline set. I also tested the flazz/vim-colorscheme version of solarized.

The main reason for this PR was not for a specific issue (my highlighting issue was just a symptom). I submitted this PR because I noticed that the pythonDot highlight group seemed entirely pointless. All it does is drop the highlighting for any . characters to Normal. This doesn't seem to be expected or desired behavior (the . should match the surrounding highlight).

Hum... got it!

Well, I could not reproduce it, not even with your suggestion under a clean env (dockerized).

But the proposed changes seems to be reasonable after all (now that you explained the reason behind it).
So I'll merge and if someone faces issues with it, a new issue can be opened, and we can discuss it better. =) Thanks for the contribution!

No problem! Thanks for merging!