python 2 to 3 conversion

[Igor Korot]

Hi,
Is there a place where there is a full list of incompatibilities between
python 2 and python 3 is available and how to fix them?

I'm looking for a way to fix following code, which runs perfectly with python 2
(and make it work with both python 2 and python 3):

if bytes[0:16].tostring() != '<some_string>':

I know there are automated tools that can help you do the upgrade, but
automated tools can do only so much....

And I am not sure if they can just add python 3 code and include version check.

Thank you.