I opened this ticket mainly to know the opinions on those modifications, I'll slowly review what I see, and provide little patches from time to time, only when the PEP8 infringement look obvious.

I think the most obvious PEP8 infringement ARE to be fixed, typically in the tutorial: The documentation is where people learn, let's teach them the right thing to do :-)

Thanks to naoki I just learnt that no spaces around binary operators are OK  when it enhance the readability (https://www.python.org/dev/peps/pep-0008/#other-recommendations) like 2*2 + 3*2.

I close this ticket, I'll just mention if I propose a patch in a new one.

Bests.