Wow. I'm stumped. Sorry for put you through all that trouble.
We could do this the easy way.
If you download GPS.py from github it should work. DexterInd puts their code on github
You see Raspbian For Robots is obviously blocking it. If you download and run that file you have full access to it. That definitely should work.
Why didn't I think of this before?
Sorry, you made no mistakes on e last commands you did. Sorry, shouldn't be this hard.
@karan you have any ideas? You wrote the code.