I know you are looking for a python plugin. But since you mention R, have you tried nvim-R? Works for vim 8+
pycharm let's you do this! this is the only thing I missed from MATLAB. you can set a breakpoint in a script and open up the debug console and see all the live variables and run code. it works perfectly and you get Python + pycharm. I'm spoiled now and anticipate having trouble moving to another language.
For the most part, when I need this, I revert to Rodeo (since it has vim bindings like RStudio's), but if I could ditch it that would be amazing. Nothing against Rodeo or other editors, but vim habits are hard to break.