After building Gnuradio 3.8.1 from source , Cannot import gnuradio

Hi, Before I installed Gnuradio from the binary package it works well.

In  Ubuntu 20.04  when I want to build Gnuradio from source, it not works...

Terminal, I received the following message:

Cannot import gnuradio.

*Is the python path environment variable set correctly?

*

• All OS: PYTHONPATH*

Is the library path environment variable set correctly?

• Linux: LD_LIBRARY_PATH*
• Windows: PATH*
• MacOSX: DYLD_LIBRARY_PATH*

I had set the path in .bashrc

export PYTHONPATH=$PYTHONPATH:/usr/local/lib/python2.7/dist-packages
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib

I had ldconfig after making Gnuradio Source

I saw all links but my problem is not solved.

thanks in advance

https://www.ruby-forum.com/t/cannot-import-gnuradio/245549