python 2 to 3 conversion

[Thomas Jollans]

On 17/06/2019 15.14, Igor Korot wrote:
> 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?

‘What’s new in Python 3.0’ is a good starting point

https://docs.python.org/3/whatsnew/3.0.html

It doesn’t list all standard library changes, but it has the most
important ones. Obviously it can't include anything that third-party
modules do.

The main incompatibility is obviously strings, and there various modules
have adopted different strategies for the transition.


>
> 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>':

No idea what this is supposed to do as you didn't say what ‘bytes’ was.
I could imagine that the tostring() method returns a bytes rather than a
str…

Also, ‘bytes’ is the name of a built-in type in Python3. You don't want
to use that as a variable name any more! (You can, though)

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

By many accounts, 2to3 doesn't work very well in the real world, at
least not any more.


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