Why Python 4.0 won't be like Python 3.0

[Thomas Huang]

Newcomers to python-ideas occasionally make reference to the idea of "Python 4000" when proposing backwards incompatible changes that don't offer a clear migration path from currently legal Python 3 code. After all, we allowed that kind of change for Python 3.0, so why wouldn't we allow it for Python 4.0?

I've heard that question enough times now (including the more concerned phrasing "You made a big backwards compatibility break once, how do I know you won't do it again?"), that I figured I'd record my answer here, so I'd be able to refer people back to it in the future.

--- Nick Coghlan

 

http://www.curiousefficiency.org/posts/2014/08/python-4000.html

[sj l]

这个帖子更好：http://lucumr.pocoo.org/2014/8/16/the-python-i-would-like-to-see/

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[依云]

On Tue, Aug 19, 2014 at 03:41:26PM +0800, sj l wrote:
> 这个帖子更好：http://lucumr.pocoo.org/2014/8/16/the-python-i-would-like-to-see/

赞！我特别喜欢这篇文章。前些天还遇到过一个由于 CPython 的实现导致 PyPy
那边行为不一样的问题呢（也是 slot 造成的）：

Python 标准说，凡是有 __getitem__ 属性的对象都可以被迭代。但是 CPython
里通过 C API 定义的类可以不这样。

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Best regards,
lilydjwg

Linux Vim Python 我的博客:
http://lilydjwg.is-programmer.com/
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A: Because it obfuscates the reading.
Q: Why is top posting so bad?