I was not aware of the dates of python versions. Thanks for the nformation.
I formed bad idea about python when last year I tried to use gain optimization script of BartJr which was written in year 2016 using python2. It failed.
I then updated it to python3 and dump1090-fa ver 6.1 and above. It was only then when I realized that there is difference in the syntax of python2 and python3.