You MUST use EXACTLY the same Python version (and the same compiler) that your ROOT binaries were built for (otherwise, expect mysterious crashes anywhere, anytime):
root-config --python-version # C/C++ calling python ;
root-config --python2-version # python 2 calling C/C++ ;
root-config --python3-version # python 3 calling C/C++ ;
BTW. Remember to “source /the/location/of/ROOT/bin/thisroot.sh” to add your ROOT executables and libraries to your environment (when ROOT is not installed in some “standard” system locations, like “/usr/[bin|lib]” or “/usr/local/[bin|lib]”).