Problem with downloading GNURADIO and gr-air-modes

when i downloaded the gnuradio from the build-gnuradio.sh file ive got
at the end a message says:


You should probably set your PYTHONPATH to:

 /usr/local/lib/python2.6/dist-packages

in your .bashrc or equivalent file prior to attempting to run
any Gnu Radio applications or Gnu Radio Companion.


and when i try to execute the gr-air-modes ive got some error message
says:

Traceback (most recent call last):
File “./uhd_modes.py”, line 26, in
from gnuradio import gr, gru, optfir, eng_notation, blks2, air
ImportError: cannot import name air

so please anyone can help by setting the PYTHONPATH i would really
appreciate it since it is for my bachelor theses

thank you in advance