NAnas·Dec 10, 2016Submission
Show HN: Python 3 with backwards compatibility features
Porting Python code from version 2.x to 3.x is not a simple task. To help, I built a version of Python 3.6 that includes backwards compatibility features. Most important is the mixing of bytes and str objects and comparisons. For example, in vanilla Python 3:
>>> b'foo' + 'bar'
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: can't concat bytes to str
>>> None < 'hi'
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: unorderable types: NoneType() < str()
In my Python 3:
>>> b'foo' + 'bar'
sys:1: DeprecationWarning: encoding bytes to str
'foobar'
>>> None < 'hi'
__main__:1: DeprecationWarning: default compare is depreciated
True
Certain changes are easy to fix with code converters like 2to3. For example, changing print statements into fun
Read the rest
ctions is trivial. I don't bother trying to handle those. There is still a lot of things that could be added. However, when porting a large code base to Python 3, I found it useful.
I hope other people might use it and submit improvements. If someone need pre-built binaries (e.g. Windows), I would be willing to do it.
https://github.com/nascheme/ppython