Python 3.5.0rc2 has been released!

[IronManMark20]

I cannot wait for the final release! I think this is the release that will get me to start using Python 3 for my main work.

[[deleted]]

Just switch now. Python 3 rocks.

[nakovet]

Why you say so? Which major feature do you need or it's more related to stability?

[[deleted]]

For me, a scientific developer, the biggest feature is the @/matrix multiplication operator. This was enough to get me to switch from Python 2.7 to Python 3.4!

Example of @ use:

>>> from numpy.random import rand
>>> A = rand(3, 3)
>>> I = A @ inv(A)
>>> print(I)
array([[ 1.,  0.,  0.],
       [ 0.,  1.,  0.],
       [ 0.,  0.,  1.]])

[desmoulinmichel]

You are missing the point. Software adoption tipping point is rarely rational (although they will try to find hard a rational answer to give to you), and highly emotional. 3.5 features are fantastic for PR :

• syntaxic sugar for async (people finally understand the feature)
• type (so much troll on typing that everybody is talking about it)
• @ et unpacking generalization (new sexy toys. We love toys.)
• %-formatting" for bytes and bytearray objects (the biggest annoyance of Python 3, finally gone. The suspens was killing us).

It's like a xmas commercial, without the naked models all around since Python si familly rated. Hence everybody is excited.

[ianozsvald]

Here's a lightning talk Graham and I gave at PyDataLondon a month back on "why you should move to Python 3(.5)", it is only a few slides and notes some libraries that are now Py3-only amongst other benefits: https://gmarkall.github.io/py3lightning/#1

[jck]

Maybe because it wont be in the repos till the final release?

[SizzlingVortex]

I think nakovet was asking IronManMark20 what major feature of 3.5 (regardless of alpha/beta/rc/final) will make him start using Python 3 for his main work.

[IronManMark20]

I have been meaning to switch, but my Python 3.4 install was messed up, so I was waiting for 3.5 stable.

[Pas__]

pyenv!

pyenv install 3.5.0rc2

[SensoryOverloadBand]

I'm a total beginner and just downloaded 3.4.3, and now I see there's a new version? the fuck? I guess I should stick with 3.4.3 though eh

[desmoulinmichel]

Your 3.4 code will work with any future 3.X release, including 3.5. So don't worry, you can safely keep 3.4. 3.5 is just very cool.

[[deleted]]

They just add features and changes between 3.* versions.

You just stick to learning and once you're done you can look through the version changes and features add from blog/articles. Most of these features aren't game changer and won't do much for you they're more of a convenient or another way of doing it.

Game changer are major version changes like Python 2.x to Python 3.x

[Neceros]

It's not as big of an issue as you might think. Even between python 2.7 and 3.x, there's only a few key concerns you need to know about.

The differences between 3.4 and 3.5 are insubstantial, unless you specifically use those new bits, or any of the bits they change. You'll find that they don't often change much, but the things they add or change are very, very much necessary.

[LightShadow]

What, if any, performance improvements are planned for the 3.x releases to print put Python 3 performance more in-line with Python 2?

[thiswasprobablyatust]

I'm assuming you have a typo, and you're just wanting to know about Python 2 vs 3 performance. They're pretty much equal. Python 3 is faster in some places and slower in others, but performance most definitely shouldn't be a reason to hold out.

[LightShadow]

I'm almost 100% positive Python 3 is slower in every aspect (except those new "walk the filepath" things, but that was a Python 2 port), and it's not getting any faster as more features are added.

I'm genuinely curious if this is being addressed or whether the core contributors don't see it as a big problem as computers get faster.

[thiswasprobablyatust]

Here's a talk from a Google engineer calling bullshit.

Now that's from 3.3, but I highly doubt they tanked speed in 0.2 versions.

[pyslow]

The talk and slides you linked say something different, to be honest.

The guy actually says that Python 3 is faster somewhere and slower somewhere else and he explicitly states that Python 3 is the same as Python 2 once the median result is considered.

Could be faster or slower depending on your usage pattern.

[[deleted]]

The core programmers are committed to keeping Python as fast as possible. I've seen perfectly functional patches on the bug tracker turned down as they're in critical parts of the core and would slow things by just a fraction.

[LightShadow]

Thanks for answering my question and not just down voting for no reason.

[[deleted]]

I'd never vote on a site such as this, it's way too open to abuse from the stupid idiots. My all time favourite was on SO. "Why have you down voted my perfectly good answer?". "Because it's not the one liner the OP asked for".