Hacker News Reader

Comment by agentultra | Hacker News Reader

I write all of my side projects in Python 3.4. I only write 2.7 because I work on Openstack at my day job. I avoid the use of Python 2 in every situation I can.

Python 3 has better modules built-in; the existing modules have been cleaned up; a cleaned up language (no more xrange, lazy map/filter/reduce, explicit byte-stream encoding); an improved language (sub-generators); optional type annotations; configurable allocators (in Cpython).

I just prefer it to Python 2 these days.

edit: And all of the upstream effort into making the language better is going into Python 3.

View on HN

As one of those crazy functional programmers who uses python, can you please explain to me what the benefit is in remove xrange, lazy map/filter/reduce, and other functional mainstays in exchange for what is essentially more syntax to do the same?

It's the other way around, they are not removed, the default implementations are now lazy. So in python 3 you get an interator:

   >>> map(lambda i:i*i, range(5))
   <map object at 0x010622F0>

and have to explicitly construct a list:

    >>> list(map(lambda i:i*i, range(5)))
    [0, 1, 4, 9, 16]
    >>>

Ah, I actually like that!

That is indeed cleaner. Thanks for the explanation.

Traversing a binary tree without an explicit stack is also much cleaner thanks to sub-generators.

    if tree.left:
        yield from traverse(tree.left)
    
    yield tree
    
    if tree.right:
        yield from traverse(tree.right)

As a trivial example.

well, range in python 3 is lazy. They replaced the non lazy implementation with xranges impl.

Same applies to map, filter and I believe reduce as well.

> I write all of my side projects in Python 3.4. I only write 2.7 because I work on Openstack at my day job.

And that's the issue.You cant be a pro pythonist unless you know both,even if you prefer 3.x .Not saying 2.x is an entire different language.Still,Python devs have to know the differences between both versions.

Let's just be thankful for OpenStack dropping support of Python 2.6!

Something I can't wait for my day job to do. At least we mostly stopped using 2.3...

Reply on news.ycombinator.com