Gnuradio library


I installed gnuradio (ver3.2.2) binary on Ubuntu. I run
and with two USRP2. And I can see results are correct.

I look at file, and see gr lib is imported (from
gnuradio import gr, gru, modulation_utils). May I know where are these
library files installed in Ubuntu? So far i could not find these files
on Ubuntu.