Live Templates to use latex completions in code.
Put this into your user folder of your target Jetbrains IDE. For PyCharm 2017.1 this would be ~/.PyCharm2017.1/config/templates. Then there will be a new Live Template called 'Latex-Completions'.
I want to thank Mike Innes for his great idea to provide for Atom the latex-completions plugin ([https://github.com/JunoLab/atom-latex-completions]). I was looking for a similar feature for Jetbrains PyCharm and found that Live Templates would be the closest mechanism providing this very cool possibility.
So I created a small python script downloading the json containing the latex mappings and created the xml for Jetbrains Live Template mechanism.
I hope someone else finds this useful too. I have looked a bit through google, but either I didn't find the right keywords or no one found this feature interesting.