Problem with downloading GNURADIO and gr-air-modes

when i downloaded the gnuradio from the file ive got
at the end a message says:

You should probably set your PYTHONPATH to:


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

Traceback (most recent call last):
File “./”, 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