So you try to access the variable through code you've input into the python scripting node ?
The problem may stem from the coding pane. I've noticed for the R nodes that non-ASCII characters written in code (in the coding pane of the R node) does somehow not appear to be sent correctly to R - you would never be able to successfully e.g. search for a string with ä ö é è etc. within the data. On the other, data with such characters sent to R and back does not suffer from this problem.