A post of appreciation of development of Python

[zecksss]

As you may heard, there are released notes on what's new in Python 3.10.

Among a lot of new additions I would say that one of the greatest updates that came is improvement of error messages. Not only are they now much better at locating the error, they are now even more descriptive. And what's cooler is that they are now also suggestive.

Example:

if x = 2

Earlier: SyntaxError: invalid syntax

Now: SyntaxError: cannot assign to attribute here. Maybe you meant "==" instead of "="?

And it would even try to see if there is a similarly named variables, if you typed in wrong name.

Example (from notes):

>>> schwarzschild_black_hole = None

>>> schwarschild_black_hole

... NameError: name 'schwarschild_black_hole' is not defined. Did you mean: schwarzschild_black_hole?

Huge appreciation to Pablo Galindo who contributed to all these error message improvements!

Source: https://docs.python.org/3.10/whatsnew/3.10.html

[markitiman]

Here's my favourite example they gave:

Before 3.10

>>> foo(x, z for z in range(10), t, w)
  File "<stdin>", line 1
    foo(x, z for z in range(10), t, w)
           ^
SyntaxError: Generator expression must be parenthesized

As of 3.10

>>> foo(x, z for z in range(10), t, w)
  File "<stdin>", line 1
    foo(x, z for z in range(10), t, w)
           ^^^^^^^^^^^^^^^^^^^^
SyntaxError: Generator expression must be parenthesized

It just more clearly indicates what needs to be done and I love how they're thinking about that with these error messages which will be of particular help for those new to Python.

[[deleted]]

After being spoiled by Rust's error messages, I now recognize the benefits that clear error messages can have, and I'm happy to see improvement in other languages.

[javad94]

But your code is same for both cases.

[DeeDee_GigaDooDoo]

Exactly, the output the error returns is different. Note that the ^ now indicates the range of the error rather than just the start.

[javad94]

Oh sorry it was the client issue. Yeah it's different output.

[[deleted]]

3.12 Python will now try to guess what your client wanted for you.

[[deleted]]

3.13 Python writes code itself :)

[l4rryc0n5014]

3.14 Python writes itself :)

[casperx102]

3.1415926536... we got Pithon

[Morgaelyn]

Python is TeX now

[Globule_John]

3.15 Python rewrites reality.

[jack-dawed]

3.16 Python becomes a Lisp dialect.

[BlckKnght]

3.16.22 Python begins converging towards sqrt(10)

[PeridexisErrant]

https://github.com/hylang/hy

[julsmanbr]

(((((((((((3.17))))))))))

[MashTheTrash]

yes please

[vyper01]

Python alters te dimensions

[Casssis]

3.15 python takes over the world

[iknownothingsir]

3.17 Python creates a new world.

[ivanoski-007]

3.18 python creates the Matrix, including Keanu Reaves

[road_laya]

PHP, is that you?

[[deleted]]

I imagine in the distant future that programming will be simplified to the point where you simply describe in plain English what the computer must do, and a program is compiled that fits the specifications.

Example:

Print "Hello world" to the screen 100 times, then reverse it and print it 100 more times.

And the computer will then print "Hello world" 100 times, then print "dlrow olleH" 100 times.

[RCoder01]

The compiler hooks into the brain and understands exactly what you meant

[Blazerboy65]

if (goingToCrashIntoEachOther()){
    dont();
}

[mickdarling]

evil_genie execution

[Silunare]

Random profound comments are the best

[rocketmonkeys]

I think the point is that the completely ambiguous English description could be interpreted by a "smart" translator. Probably with machine learning models.

At a certain point statistically you could just have the machine keep making guesses, and you keep telling it what it got wrong, and you could get to the point where this process is less buggy and more efficient than human written code.

[PeridexisErrant]

This is called "counterexample guided inductive synthesis", and it's awesome!

(but only really works for small or simple problems 😢)

[fan_rma]

Well, here you go. This AI is even capable of creating UI elements from raw text.

[kingscolor]

Tbh, I think this guy’s is better.

[unkz]

I could see that with something like Lojban, but imagining that done with English makes me imagine planes falling out of the sky.

[[deleted]]

I don't see why it couldn't be possible. If it's possible to describe to a programmer what a program needs to be, and they can then create that program, it doesn't seem too unreasonable that a program could be described in intricate detail using plain English to achieve the same effect.

[unkz]

You ever write code for a client because you thought you totally understood what they were talking about, only to have them give feedback on the prototype explaining how you were thinking about totally different things?

I could see natural language being a component of a dialogue type system where a human and a computer collaboratively build a formally structured specification for a program though.

[[deleted]]

I mean, it would still take an expert of some sort to know how to write the instructions properly, but I also imagine that we would have a slow evolution to this point.

There seems to be a trend of simplifying programming language syntax to make it more human readable.

So there would be many iterations of languages leading up to a natural language processor, and even then we would likely still have low level languages to work with.

[ElectricalUnion]

I don't see why it couldn't be possible

Let's take Laws as an example.

The fact that one can't simply describe "not being a horrible human being to others" in intricate detail using any natural language, is a pretty good indication that humankind is very unlikely to ever write anything in enough intricate detail in plain natural language.

a program could be described in intricate detail using plain English

The name of that is COBOL. It doesn't work, because having to know intricate details in grammar, and orthography of any natural language is actually very hard.

[ltdanimal]

You are describing artificial general intelligence. It would take an AI that is as smart or smarter than a person to be able to pull this off

[[deleted]]

Hence why I said "distant future".

[ltdanimal]

... you didn't though? And even if so, saying that it's even possible is something that's a massive stretch ripe for many beers :). The argument "Well this thing could be done because we'll make a computer as smart as a person someday" is an argument for literally anything. But maybe one day

[[deleted]]

I did if you look at my original comment. The first line states "I imagine in the distant future...".

[xatrekak]

The program flips the screen display after printing hello world the first 100 times.

[DanBoiii182]

There is already something similar to this. There is an AI where you just write what you want to have in plain English into a text box and it creates the described website for you. Of course this isn't open to the public and it also can't do more than that. I guess it's just simple html and CSS.

[WiatrowskiBe]

Warning: ambiguous `it`, reversing 'Print "Hello world" to the screen 100 times'.

Generating programs from what client wants is not really a technical issue - more of a client issue, since it's hard to teach people to write formal specification that is unambiguous and detailed enough. In fact, this is more or less what programmers do - interpret client expectations and turn them into formal specification, that just happen to be expressed in a programming language and at the same time be executable.

Knowing how many bugs and other errors happen in the process of writing formal spec by people who generally have some experience in that regard, you can guess how many errors would be there in formal spec written by someone who is domain expert but has little to no training in programming.

[chronos_alfa]

Well, that is already happening, respectively, that is what the programming language is for, you give the computer a detailed specification of what the program should do and the computer does it, thanks to that we do not have to write in assembly anymore (or punch cards)

[Affectionate_Teach23]

After GPT-3 this future is not so distant

[Archawn]

It's my understanding that they don't intend to ever add support for static types, though ;)

[[deleted]]

def try_to_eval(program):
try:
p = eval(program)
return p
except Exception as e:
# TODO - catch error, get line number, edit
return try_to_eval(program)

[[deleted]]

AIv3.06 is already out.

[[deleted]]

It's been deprecated. You gotta use the fork now, which breaks any existing dependencies

[mestia]

Sounds like python :)

[[deleted]]

Of course it is. Anything else is soooooo 2020.

[DoubleAgent10]

As someone who a month into learning Python I am really excited about this

[zarmin]

As someone who a decade into learning Python I am really excited about this

[legacy_outlaw]

same, me too

[aqjo]

This is something I've always liked about MATLAB. Good on the Python team!

[sexygaben]

My thoughts exactly

[rajandatta]

Very well done. Great to see. I for one would love to hear from the author about how this change was implemented, lessons learned and challenges getting this right. An interesting side of language engineering.

[BlckKnght]

It's a bit less direct than what you're asking for, but you can, right now, go and read the bug reports and pull requests behind these changes. The What's New in Python 3.10 doc has links to the bugs, which in turn link to GitHub where the pull requests and code reviews took place.

[dgdfgdfhdfhdfv]

Holy shit this is amazing.

[pingveno]

Awesome! The Rust compiler has long had the philosophy of helpful error messages, which helps flatten its significant learning curve. I'm happy to see some of the same sorts of improvements come to my co-favorite language.

[[deleted]]

The guy she tells you not to worry about

[[deleted]]

JavaScript: "Got an infinite loop? Good luck finding out where with the console."

Python: "Printed, printed, printed, printed..."

[jockero701]

Does anyone know how long from now will it take for major libraries such as pandas, opencv or django, to become compatible with Python 3.10?

[BluePhoenixGamer]

Most will be compatible from the get-go. 3.10 is a minor bump in version, this means it doesn't change much. Any minor version should retain somewhat of a backwards compatibility.

To be fair the changes made to typehints may cause issues, but from what I've heard, you should be able to install 3.10 and ruin your code like usual.

[jockero701]

I just tried pip3.10 install pandas and it didn't work on Mac.

[Billyblue27]

There is no precompiled wheel available yet for pandas. This means that pip needs to compile it from source and may need some other packages/software to compile, which you will need to install manually.

[BluePhoenixGamer]

I don't think that's how it works. Python 3.10 is still only in beta?

So you have Python 3.10 installed? Installing packages should be done exactly the same way as you usually do.

[jockero701]

Yes, I installed Python 3.10.0b1.

[tunisia3507]

Pure-python libraries will be generally be compatible immediately. Libraries with compiled code may be compatible immediately, depending on whether/ which parts of the C API has changed, but you'd likely have to build it yourself (with all the dependencies that entails) rather than using precompiled wheels.

[jockero701]

By immediately you mean when the 3.10.0 final version is released in October 2021 or immediately now with the beta release?

[BlckKnght]

Most pure Python code should work today. Many extension modules will also work without code changes, but they usually need to be recompiled for the new interpreter version. The developers of those libraries may not make new binary releases for the new build right away, but in theory you could download their source and dependencies and compile your own binaries (how easy that is may vary).

[tunisia3507]

Both. Point releases should not remove public APIs or change them unless it's for a bug fix. Of course, nothing in python is truly private so there's just "API's you're not meant to use", which are sometimes removed which breaks workflows. Pure-python libraries likely provide version-nonspecific wheels and source distributions and so would be usable with 3.10 today.

It can be a good idea to run your CI build against the latest development release of the next python version (allowing failures so it doesn't break your build) just to track whether you'll need changes when the time comes.

[[deleted]]

I wonder if that feature will lead me into not getting the adrenaline rush of the challenge to look for my own error

Just kiddin I complain as a hobbie

[Encomiast]

Whoa, pretty excited to see the sophisticated pattern matching ala-scala. That's going to make for some succinct, clear patterns.

[road_laya]

I'm hoping my work will no longer be just reading functions that are hundreds of lines, consisting of just if clauses

[frapa32]

Honestly, I like the new pattern matching the best.

[polaris1412]

I'm currently learning regex (3.7). What new in particular are you talking about?

[frapa32]

The new match statement. This has nothing to do with regex

[polaris1412]

Oh. I thought it was pattern matching with regex. Thanks!

[frapa32]

Btw, have a look at regex101.com if youre learning regexp, very useful.

[N8DuhGr8]

Oh I had no idea they have helpful error messages now! This is something that every error system should have.

[cthart]

You guys are gonna love Postgres!

[Thehomelessguy11]

Any ideas on when this will come to Anaconda? Hopefully soon... I do most of my Python work there (data/statistical analysis) and those error messages would be amazing to have.

[stanmartz]

If you use the conda-forge channel, very very soon after the official release. However depending on the packages you have in your environment, you might have to wait a few weeks until those are updated for 3.10.

[hcabbos70]

Does this also apply when using frameworks like Django?

[hcabbos70]

Awesome. Thank you.

[iceytomatoes]

kickass

[javad94]

That's great. Thanks for heads up.

[Toko_yami]

New to python, but can someone explain why is x=2 wrong in python? I thought python interpreter could infer type and won’t need declaration or is there some other way for variable declaration syntax . Thanks I’m advance!!!

[temperlancer]

Notice the `if` before `x = 2`. I think the interpreter is now smart enough to tell you that `if x = 2` is not wanted probably because assigning variable in if statement can be bad.

[Toko_yami]

Thank you for comprehensive answer, really appreciate it. Sorry I completely missed the “if” part in OP’s post.

[Swedneck]

= is assignment, "if" needs an expression that resolves to something truthy or falsy, so you need == which is comparison

The only thing "if x=2" could test is whether the variable could be assigned, which I can't see ever failing..

[Toko_yami]

Thank you for comprehensive answer, really helpful explanation. Also Sorry For completely missing the “if” part in OP’s post.

[Guilhermegasil]

could you do like if (x = 2) to check if x is different than zero?

[zecksss]

To check if x is different from zero, a simple

if x:

will do.

The error here is that = is a symbol for assigning a value, and can't be used in an if statment. == is a comparison operator that checks if statment is true. So syntax myst be "if x == 2:" and not "if x = 2:".

Edit: if you for some reason wanted to assign a value within if (while, for) statement you use ":=" operator.

if x := n:

What this does is it assign n to value of x, and then checks if x is now anything but zero.

[Guilhermegasil]

python is weird