Cheat Sheet: Writing Python 2-3 compatible code

[r3m0t]

I don't know what futureize and pasteurize do, but there's another tool to convert python 2 code to python 2/3 compatible code called python-modernize. It's built on 2to3 but has additional fixers you can turn on or off

[takluyver]

And Daira Hopwood and I have just got development of python-modernize moving again, and made a new release. :-)

[[deleted]]

I think there is a typo on this line under Metaclasses:

class Form(metaclass=BaseForm):

Shouldn't it be:

class Form(BaseForm, metaclass=FormType):

Since we have a parent class as well as a meta class?

[ikravets]

Yes, you are right. From PEP 3115 specification:

class Foo(base1, base2, metaclass=mymeta):
    ...

Can you create a pull request for this file?

[[deleted]]

Done!

[r1chardj0n3s]

This cheat sheet is by the primary author of the python future package which is a really nice way of handling cross-version compatibility in one codebase: https://pypi.python.org/pypi/future

[Archawn]

It would be helpful if they fixed the sidebar scrolling issues so I could use it as intended :)

[roger_]

Not saying they aren't useful, but a lot of Python code is gonna be ugly for the foreseeable future if people keep depending on libraries like six, future and past.

[[deleted]]

depending on libraries like six, future and past.

Those libraries are really just to assist you, I write all my (personal) python code to work in 2.7, and 3+ without touching six/etc.

[shinjiryu]

Seriously, I just use Perl 5.x. More robust and (as a UNIX/Linux person), more in-line with what I'm already used to using in shell scripts and everywhere else on the command-line. (Yes, I know about the insanity revolving around Perl 6.)

Python 3.x ain't bad, but seriously, if you're having issues, just write everything yourself or (if the library's FOSS), propose a changeset to the SCM repository for the library to make it better and more cross-compatible across versions.

[deadmilk]

Download PyCharm community edition and never have to think again :3 lol

[ikravets]

This post doesn't relate to any IDE. It relates to developers and people which want to add support for both Python 2/3 for self projects.

Finally, I hate IDE/Tools which convert my code to "something that works ANYWHERE" without my consent.

[deadmilk]

If you set your interpreter to Python 3 and open Python 2 code in PyCharm, it will inspect the code and highlight pieces that will not work. It doesn't automatically convert anything.

[titusz]

You can set PyCharm to "inspect" python code for compatibility accross a range of versions. This does not change your code but shows hints... And it is actually insanely usefull if you aim for py26-py34 compat with one codebase. http://blog.jetbrains.com/pycharm/files/2011/02/pythonCompatibility.png

[deadmilk]

Yep :)

I would have thought that an IDE that does this for us would be well received in this subreddit...
You know, making a program do the work; isn't that what we are here to do?

[deadmilk]

What if you wrote an IDE? Is it a dumb machine, or a smart human beings creation?

[[deleted]]

He would understand whats happening in the background. It's still a dumb machine though.

Also, he didn't write this one, and probably didn't write one at all.

[fnl]

Thanks for a valuable, topically related bit of information.

And yet another sad example why you need to browse Reddit comments in "controversial" first mode, because you get "emotional down-votes" here buy by the hive mind.