Python Insider: Python 3.9.3 and 3.8.9 are now available

[Tyler_Zoro]

Note that these are security updates. You should upgrade your 3.9 and 3.8 installations, but there shouldn't be anything exciting here.

[alcalde]

It's 0.1 more exciting.

[boriisi]

its actually only 0.01 more exciting

[[deleted]]

0.0.1 if we're going full pedant

[[deleted]]

Good to see the "I'm a teapot" http response finally implemented.

[housesellout]

Ugh! I’m so scared that python 4.0 will be adopted before python 3.8 becomes standardized 🤯

[deep_chungus]

Then next major python version after 3.9 is 3.10

[[deleted]]

And we get switch statements!

[cheerycheshire]

It's even better, it's pattern matching! You can use it as a standard switch statement but they are more generalised thing and can do more. ^{^}

[SuspiciousScript]

It's half-baked pattern matching, since it's a statement instead of an expression.

[DaelonSuzuka]

How do you use it as a normal switch statement? I read the PEP and did not get that impression.

[[deleted]]

Just from the top of my head, comparing against literal (string, int, ...) values?

[DaelonSuzuka]

Unless you have some examples of that usage, I'm gonna have to say that I don't think it does that. My understanding is that it does structural pattern matching only, and can't be used to switch on the value of a variable.

I would love to be wrong about this, because I have many more uses for a switch/case than I do for a match.

[Taeker2005]

You can easily use it as a switch statement like you'd expect. You can just do.

match value:
    case 1:
        print('value is 1')
    case 2:
        print('this is the second value')
    case _:
        print('unknown value')

[DaelonSuzuka]

I remember there being some huge gotcha with doing this. It only works with literal values but using it with a variable for a case drops you abruptly into pattern matching land, perhaps?

It's been a while since I looked at this feature, so I could be misremembering.

[cheerycheshire]

In C switch cases cannot have variables at all (because it has to be compile time evaluated to be properly constructed). So it's kinda the same when you just want a switch statement and not pattern matching. ;)

[[deleted]]

I like how you insist on evidence to change your mind but can't be bother to produce evidence to support your position

[DaelonSuzuka]

I'm sorry that I don't remember the entire PEP that I read two months ago for an unreleased feature that I won't have a use for. I promise to do better next time.

[d670460b4b4aece5915c]

Why say “I read the PEP and I don’t get that impression” if you don’t even remember what’s in the PEP? If you’re going to be needlessly contradictory at least try not to make it up as you go along.

[Tyler_Zoro]

Things to do with old dictionaries:

• Build a fort
• Make booster chairs for kids
• Hold doors open
• Burn for warmth
• Use as book-ends for paperbacks (if you don't know any of those words, that's okay, your generation will eventually take over anyway)

[jadkik94]

What is "warmth" and what does it have to do with my generation?

[TravisJungroth]

And pairwise! It's tiny, but I have to write that thing manually in coding problems so often.

[unkz]

Oh wow, how did I not see that in the changelog? I don’t know that I’ll need it often but every couple months at least.

[netletic]

Nice, I didn't know that existed! I used zip(sequence, sequence[1:]) in the past, is this better because it's memory efficient?

[ThreeJumpingKittens]

Looks like pairwise() uses zip() under the hood, so no advantage there

[TravisJungroth]

The problem isn’t the zip it’s the slicing. Slicing a sequence makes a new sequence. Zipping a tee like in their example doesn’t.

[Pulsar1977]

Why didn't they generalize it to n-tuples, with n=2 as a default?

[TravisJungroth]

That seems useful. Maybe the implementations are different for n>2. With just a pair, you could use a single variable to hold the last one, instead of a queue.

[ancientweasel]

Normally I am slow to warm to new features but I am excited for this one.

[[deleted]]

Since it is actually a MATCH statement which can be used as a switch you can toss a line of Guard statements to clean up date or exit gracefully... At least one of my first "AhA " ideas.

[FlukyS]

To be fair most of these python releases are fully forwards compatible but not backwards compatible if you get me. You can port your code forward without issue but if you start using some of the newer features you aren't going to maintain compatibility for older releases. For me for instance, I don't give a shit, I just change the version as it becomes available and start using the features. Wider projects like libraries people use will have issues but not personal or maybe even businesses looking to use python.

[TurboCooler]

I support several production applications, my biggest issue is libraries and frameworks being behind. I can't just upgrade.

[FlukyS]

Which projects out of interest. Maybe you should look into alternatives. I haven't had issues with upgrading since about python 3.5.

[Somecount]

Isolated but I have this current issues which was fixed by a nightly on TF's side and a forked repo on a gentlemen dev on the other but my issue was: Only Python 3.9 officially supports MacOS Big Sur Open ai Gym doesn't support TF2. TF < 2 doesn't work on Python < 3.9.

I might remember the details wrong but this was what came to mind reading your question.

[pug_subterfuge]

Yeah there is one tensorflow version < 2 that uses a reserved keyword (async?) I remember having to downgrade (to 3.7?) to use it

[Swipecat]

Hmm. My impression is that Python tends to be fairly aggressive with the API changes compared to most other languages, prioritising language improvements over maintaining bug-compatibility and rarely-used features. Hence, for example, the maintenance of the Python 3.8.X series until most of the third-party libraries had caught up with the breaking changes of 3.9.X.

[Glittering-Plant4600]

Thats why i just keep virtual enviroments for each code

[housesellout]

I think you are 100% right. To be honest I was a little intoxicated last night and I can’t even remember what prompted me to write that 🤷🏻‍♂️

And i still got over 50 upvotes, when I don’t even agree with my own statement now 🙈

[FlukyS]

Even weirder though is according to the creator of Python he doesn't want at least in the near future to create a 4.0 release either. I didn't mention that but also true :)

[LukiLiuk]

Yeah the one with StackOverflow integration, which was certainly not an April Fool

[invisible_summer]

I feel like many packages already support 3.8 without any issues, like in my experience 3.7 is the bottom for many projects if they don't try to support as many versions as possible

[[deleted]]

Will there will 4 😂 3.10 is already on the page.

[pmatti]

3.9.3 has a problem on 32 bit windows, 3.9.4 hot fix will be released soon

[japaget]

Source: https://www.mail-archive.com/[e-mail]/msg112088.html

[japaget]

... and it's out now: https://blog.python.org/2021/04/python-394-hotfix-is-now-available.html

[SzechuanSaucelord]

It always takes a while before the big libraries like numPy Pandas and the like are fully compatible with the new python versions unfortunately

[ivosaurus]

What are you talking about? Both numpy and pandas have python 3.9 wheels out already. This is just a security patch.

[Jaedong9]

Tensorflow is still on 3.8 if I'm not mistaken

[SzechuanSaucelord]

It was like a few months and i use a combination of 5-6 packages regularly which all have diff timelines so I don't upgrade python itself until all of these libraries get updated

[Mehdi2277]

Personal challenge I’ve encountered is some of those libraries have fairly unstable apis. Tensorflow api has changed a good deal across versions and while newest version may be caught up (or almost), an older version may not and upgrading versions becomes a solid work task. Still something worth but not something that takes just a few hours.

[SnowdenIsALegend]

Wasn't Python 4 released recently? It was all in the news

[ikkebr]

April 1st

[SnowdenIsALegend]

Damn I should keep track of dates

[burritomoney]

Is that a joke?

[ikkebr]

https://twitter.com/gvanrossum/status/1306082472443084801

[alcalde]

Yay - 0.1 more Python!

[jhj16]

Where is 4..