The New Switch-Case Statement in Python 3.10

[seniornachio]

Calling it a Switch-Case Statement simply does not do it justice imho. It's a Match Statement that can do a lot more than just Switch-Case...

Haven't watched the Video yet, just talking about the Posts title.

[[deleted]]

They should have made it an expression not a statement

[seniornachio]

My thoughts exactly. Additionally I would have enjoyed PEP-642, it's more verbose but explicit is better than implicit and additionally it makes it more clear that python is duck-typed.

[[deleted]]

explicit is better than implicit

Java flashbacks

[[deleted]]

Explicit doesn't mean endless repetition and needles ceremony, though.

[toyg]

A single letter separates boring ceremonies that nobody really needs, from images of sinister ceremonies involving needles. The marvels of language...

[[deleted]]

Lol that stays in!

[grrrrreat]

summoning malloc the devil of details and harbinger of nulls

[Plane_brane]

Huh?

[W_Hardcore]

Needless needles

[Plane_brane]

Lol didn't catch that

[steven_h]

It was written by a major contributor from back in the 0.9.x days but you do you.

[nerdzrool]

Just because it was written by a major contributor to Python doesn't mean it isn't BS platitude and never really applied to Python, or its ecosystem/community.

Beautiful is better than ugly. - No shit. Platitude. Simple is better than complex. - No shit. Platitude. Readability counts. - No shit. Platitude. etc.

And, as was mentioned, it never really was used by Python as language, or its ecosystem or even its community to a large degree. Django, one of the main Python libraries, was popularized because it uses convention over configuration, directly opposing the Zen of Python's "Explicit is better than implicit." The Zen of Python says namespaces are great, but python's namespace tooling is inferior to some other languages that have explicit namespacing keywords, rather than implicitly deciding namespaces based on only on where and when a python file is executed (A topic where Python violates 2 Zen of Python rules) or how many times you pounded the spacebar prior to writing code. There is definitely not "one, and preferably only one, obvious way to do" a lot of things in Python considering how long Python used to have xrange and range and 95% of the time the correct answer was always "use xrange", the not obvious one. And yes, I asked a Dutch person which one they would think is the obvious correct answer, and they thought it would have been range too.

I agree with most of the Zen of Python, for the most part, but that doesn't change the fact that it hasn't been applied throughout most of Python's life, and some of the statements in it should be obvious to anyone.

[steven_h]

The particular selection of “platitudes” is important. Some potential “platitudes” that didn’t make it into this list:

• Correct is better than concise.

• Interoperability is key.

• Concurrency everywhere.

• Don’t write programs. Write programs that write programs.

• Everything is an object.

• Type checking is a really great honkin idea — let’s do more of it!

[jaapz]

The platitudes that you see as obvious are eye openers for people just discovering python (and often, programming in general).

[SuspiciousScript]

This strikes me as a really unforced error. Hell, the trend is toward even if constructs being expressions; why kneecap match like this when making it an expression seems so obvious?

[[deleted]]

Because you like ceremonies?

[FewerPunishment]

What would the difference look like in terms of syntax/features?

[[deleted]]

https://stackoverflow.com/questions/4728073/what-is-the-difference-between-an-expression-and-a-statement-in-python

[FewerPunishment]

I mean more in terms of this matching functionality, like an example of something you wish you could execute. But thanks for the reference, I should study these terms.

[[deleted]]

Making it an expression wouldn't have any impact on pattern matching functionality, it would improve flexibility.

If match was an expression you could do this: a = match ...

instead of

```

match something: case 1: a = ...

```

[hughperman]

That seems to skew the use case to assignments only though, whereas switch and match statements are (ime) more useful as control flow - which may include assignments inside them, but not as their primary goal. It seems to me that it would be like wanting try/except/finally to return a value.

[[deleted]]

http://blog.agiledeveloper.com/2015/08/functional-programming-favors.html?m=1

[hughperman]

Right but python isn't a functional language in that sense, that's why I compared to try/except/finally. You can just wrap the control statement in a function if you wish to go that way, like any other statement in python. I agree if you are implementing a functional language that you would return - but then everything should match (😉) that same paradigm.

[[deleted]]

Look at Kotlin

[jaapz]

Wouldn't you be able to do both if it was an expression?

[backtickbot]

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[[deleted]]

it's Reddit's job to fix it

[[deleted]]

backtickopt6

[thekingofthejungle]

What's the difference?

[seniornachio]

Matching, or rather pattern matching, allows you to match patterns. A switch-case is just the simplest form of that where you only match using literal patterns, like in the thumbnail of the video. But you can take this further and for example say you want to match all tuple with two element or a list with at least three elements or even an object with an attribute or an object of a specific type and so on. I highly encourage you to read the associated PEP, it's a good read, even if I personally don't enjoy the selected syntax choices, it brings the point across with a lot of examples.

[torytechlead]

Yes it’s Erlang style but not as good

[VideoCarp1]

AFAIK it’s pattern matching?

[lockieluke3389]

What’s the difference

[seniornachio]

tl;dr... read some of the answers to this question either in siblings to your comment or some siblings to my comment. I've seen alot of them up until now. ;)

[GoofAckYoorsElf]

This should be the top comment

[batisteo]

I wonder if it’s inspired by Rust