Python’s tug of war between beginner-friendly and advanced features
aroberge.blogspot.com
aroberge.blogspot.com
Python has added lots of features to stay current with the latest trends in programming languages, but this has come at the cost of complexity and redundancy (e.g. look at all the ways to format strings or do filesystem operations). And many of the new features such as type annotations have a compromised design due to their being added to Python late in the game. Python's "batteries included" approach of a large standard library was a great asset in the days before package managers but these days I think it would be better to start with a much leaner stdlib and add things in more stringently.
I would also want some kind of a typing support, ala Pydantic built in. If for nothing else, I would like to know wtf is this function taking in as args.
Can we also run this in a browser!? One can dream.
There are other bundles that are very popular for a reason. Conda. That's all you need to know. People want stability of dependencies, not wild wild west on pulling libs from random github repos.
It's not a package manager and it does not provide any environment isolation of its own. Conda provides both of those things, and quite a bit more.
They are totally different tools. Conda is more like Homebrew than Poetry.
What Poetry and Conda have in common is a not-really-bad dependency resolver.
That experimental library could even be backed by other packages, so you could iterate on the interface while allowing other packages to continue to improve the core. But the assumption is for any clearly solved problem, these “batteries” provide one recommended way to solve the problem, and as of now it’s either the only or at least not the worst way to do it.
Claiming that a language user should be prepared for certain parts of the language to disappear is a perfectly reasonable idea. But in practice it does not work. Because either it can or cannot be used, and if it can't be used it is a waste of time, if it can be used it must be supported.
Once people use a library, there will be pressure to support it forever and the mindshare switch is a real cost. A language bleeds users every time it drops a feature. The Python namespace is still polluted by documentation and tutorials talking about how to do things in v2 too.
But Python has a very different release schedule. Rust's nightly releases nightly and stable every six weeks, while Python only releases once a year. I don't think it could adopt the same model.
Well, it can. That's what you get when there's no official package and you depend on third party packages that change all the time (e.g. common in the Node ecosystem, in GTK+ land, etc.), or are abandoned, etc.
Compared to that, a scheduled, anticipated process for candidate packages to include in the language (or remove eventually) is much easier.
...although that might all be the fault of aws-cli. Which by the way doesn't install on a vanilla Ubuntu 20.04 ami via apt which is just... really really bad.
Aws cli continues the inexplicably horrible aws interface that makes me shake my head at people lauding their might, along with their console.
The console rewrite... anyway, pip seems to be a headache, certainly not as good as gems.
I had a quick look in pip and install order is predicated on requirements order https://github.com/pypa/pip/blob/c188d1f08f1a4a2c0a03e397f15...
I'd instead aim for a language that supported interface/trait/typeclasses with a huge standard library of those that allowed writing uniform benchmarks and unit tests to every implementation that shipped simple implementations for some of those and made it easy to use different implementations and experiment with them.
This seems like solving just dependency injection instead of trying to solve every library ever, which seems a much more realistic problem to solve correctly, or at least in a way better way.
Every common X means thousands of complex things. There are over 9000 RFCs (insert Vegita meme). Even more popular APIs, libs, algorithms, whatevers.
Even basic support would be near impossible. A constant race between what constitutes basic and releasing it. (Plus upkeep/maintenance, as things continue to evolve at a rather fast pace.) And if the language enjoys at least a minimal level of successful then a lot of non-stdlib packages are likely to become standard by convention.
It's no wonder that new languages nowadays start with minimal stdlibs.
(I just noticed that there's an SMTP server in Python3! It's ... great, I guess. But there's no DNS resolver library. So either the SMTP client (and now server) packages do not handle anything related to DNSSEC / DANE / TLSA / MTA-STS / DKIM / DMARC and others, or they bundle it. Sure, maybe it's enough to outsource these to the upstream SMTP server and the SMTPd package is just for "testing" ... but, this just shows how arbitrary "commonness" is.)
I know the mantra is that the standard library is where things go to die, but I believe that to be cultural. I still have code running somewhere probably that uses the cgi library, which was perfectly well-suited for a Windows serve where the page in question got an average of seven hits a day, never to scale much beyond that (you'll have to trust me on this, for amusement I reviewed ten years of logs for just that page to find nothing out of the ordinary, and there are reasons it would not need to "scale" in the future).
Each library and each string-formatting method and so on is a choice, and those choices impose a lot of speedbumps and cognitive friction.
I definitely think they’re onto something. Dependencies are a hard problem to solve.
Modern build tools like gradle work great at resolving deps, until they don’t and at that point we’re in for a world of shock at just how complex dependency resolution can be in large projects.
I was sad to hear about the change to ReScript though. ReasonML targeting the browser and native seemed nice to me, although I do agree the documentation situation and DX wasn't ideal.
The facilities provided by a browser are almost (but not quite) a complete superset of those provided by an OS. file io, peripheral io, etc. Can all be done via the browser. Additional facilities are provided too (security/sandboxing).
Now a common model has arrived (dom + js) allowing multiple browsers to just run your app.
I’m not sure browsers are faster (there was a thing called pepper api in chrome and nacpi or something in firefox - i’m not familiar with the space) that allowed native code to run.
I’m not sure browsers are generally faster than native OS binaries, but they are an easy to deploy to environment that doesn’t need syscall emulation like freebsd can do for running linux binaries.
Why not let the OS do more and more of the complicated technical stuff, simplifying the deployment of web apps because now we don't have to know a thousand different bloated libraries, just a slowly updating set of OS APIs.
For what it's worth, there are a lot of good interesting languages out there that aren't Python and have pretty good library ecosystems. Kotlin, Elixir, and Elm come to mind. But they don't exactly fit the Python niche.
What you're describing sounds to me like a modernized Common Lisp with commercial backing. Rework CLOS a bit, clean up some of the other crufty old weirdness, and give me a big selection of high-quality well-supported libraries like Numpy, FastAPI, Trio, etc.
The advantage of doing it in some Common Lisp derivative is that things like React JSX are pretty much "free" and wouldn't much seem out of place, whereas in Javascript they need a whole separate build/compilation step and are often portrayed as black magic fuckery.
edit 1: Arguably Julia could be used for a task like this, but its library ecosystem and language runtime are heavily skewed towards numerical computing and data analysis.
edit 2: Raku also sounds like a possible candidate here, but it obviously lacks widespread adoption and last I heard it fell significantly short of Perl 5 performance. I'm not sure what kind of library ecosystem it has nowadays and I doubt we're going to see big commercially-backed library development efforts for it, soon or ever. Perl 5 has a huge ecosystem of course, but it's such a nasty warty language with nasty warty tooling.
http://gigasquidsoftware.com/blog/2020/01/10/hugging-face-gp...
http://gigasquidsoftware.com/blog/2020/01/18/parens-for-pypl...
http://gigasquidsoftware.com/blog/2020/01/24/clojure-interop...
And you can try it out in nextjournal online notebooks like here: https://nextjournal.com/kommen/gigasquids-libpython-clj-exam...
use DBI:from<Perl5>;Right. It clearly doesn't have a strong enough offering at the moment to attract anyone beyond a few early adopters.
> last I heard it fell significantly short of Perl 5 performance
Likewise. I'm pretty sure Perl still roundly trounces it for a lot of operations, especially in regex processing. I think it will need to be significantly faster than Perl before it will have a chance at gaining significantly more adoption.
> I'm not sure what kind of library ecosystem it has nowadays
The raku.land directory has less than a thousand packages and many seem to be jokes, unloved, poorly tested and documented, version 0.x, or even 0.0.x. [0]
The standard library is a different ballgame. It's generally well designed and very large, cutting out the usual blizzard of folk reinventing the wheel for basics. So that's good.
> I doubt we're going to see big commercially-backed library development efforts for it, soon or ever.
I agree.
> Perl 5 has a huge ecosystem of course, but it's such a nasty warty language with nasty warty tooling.
This is where I think Raku's strength lies.
A lot of the effort that went into Raku was to build a platform that could just directly use tooling and libraries of other PLs while insulating developers from their downsides.
That way you get to use Raku tooling, syntax and semantics at the surface level with other PLs' tooling and modules and performance. Kinda like using C code in a non-C PL, but generalized to using code from any other PL in Raku.
The exemplar was supposed to be Perl, but it was also supposed to extend to many other PLs. Starting 7 years ago this became the Inline family.[1]
Inline::Perl is the most mature. Imo it's remarkable. But it was always supposed to just be the first one to get the polish to demonstrate that the approach works and works great. About a year ago the author behind it said it was nearly time to do the same for Python modules. And now I see a GSOC proposal to do that.[2]
The Inlines hide the warts (though you do have to read the modules' documentation to know what their API's are etc).
I think the impact of Inline Python will be huge because it takes away the complaint about reading Perl documentation and code. Instead you read Python API docs but get the benefits of using Raku.
(And, in the wings, there's Inline::Ruby, Inline::Lua, and so on.)
[1] https://raku.land/?q=inline
[2] https://github.com/perl-foundation-outreach/gsoc-2021-ideas/...
While there were some quirks, It worked rather well.
This is offensive. Whether the people who work hard to make and share (for free) half baked libraries are addicted to drugs is really not part of the main thrust of your argument. You could leave it out, save words, and not have distracting comments from people like me while still making your point.
No one in their right mind thinks about people building free libraries on GitHub as nothing but positive thing. Come on. I am offended that you’re offended by this.
Usually, I would apologize for saying something offensive, but I guess someone will get offended on the internet. If I said “Wild Wild West” then may be some Texan would be offended by it.
Intention matters. Smile more and be tolerant, no offense :-)
If you feel love, share love. xx
Leaving them out would communicate the core idea, but not the emotional tone they wanted it to have.
(And it's obviously not about literal junkies, it's meant as "random people who don't know what they're doing").
This, and library documentation. It's probably the single practica issue I have with D and Nim. They seem to have fairly robust standard libs but when I look for something specific it always turns out this feature is missing, outdated, or badly documented.
import cv2
Yes, Stack Exchange, I know OpenCV can do this for me, but integrating that into my package dependencies is time down the drain which I am never getting back.- A simplified/sounder natively integrated version of Typescript's type system - Javascript's easy notation for manipulating objects - None of Javascript's other baggage/cruft - Something akin to go routines
Basically, something with the performance of Go/Java (so there would be no need to rewrite your code once it starts serving millions of people) but the elegance of Typescript.
Not sure if this is similar to your vision of a "next Python" but it feels somewhat similar.
Basically I think right now:
C -> Zig
C++ -> Rust
Java -?-> Go
Python/Javascript --> ???
With native typing we could get a language as fast as Java/Go but with the cleanliness of Typescript.
The apps may be heavyweight, but the runtime was designed to run on set-top boxes 25 years ago.
Not sure if that's because I'm a beginner or if it's just Spark itself, but Scala errors are impossible to decrypt.
Time to bump Scala to version 3 so that you don't have the 22 case class field limit anymore. :)
See here: https://dotty.epfl.ch/docs/reference/dropped-features/limit2...
That is what I mean though - but I would replace "Java" with python here. Just stay away from all the complexity and write python code. It's pretty simple and some people argue it's the better way to use Scala.
Just like how you don't have to use type annotations, generators, decorators, context managers in python.
Same for libraries.
At some point you will stumble upon a library that forces you to understand them or you even write one yourself, but that is not something that stops you in the beginning.
Go got this right. If you want to read code, contribute to a large code base, folks will be using the features of the language, including the weird ones. Go has kept things very simple (relatively) in terms of core language. Some things were beyond basic (error handling? no generics?) But boy did it make it easier for contribute and understand code.
def Hi() = "hi" Hi() Hi
Yes, those two variants both work?
Sure, but in that case, is python really beginner friendly? I don't think so. I had the impression we were talking about starting out with the language and building the well-known todo-list to learn the basics.
Also, golang is a rather young language and it will go the way that all languages go: it will get more and more complex because the more experienced developers want to improve their productivity with better language features. Remember the "no generics" thing? Well, now the generics will be added - I predicted this to happen. And just wait, other features will follow...
They've been adding some really more edge / line noise type features. Consider the walrus operator? You can do pretzel magic with this which make figuring out scope and what happened to what difficult.
I love the old way.
with open(…) as f: for line in ...
And I wish they'd just made more things iterable maybe or fixed some of the regex match stuff?
Having said that, isn’t Deno close to what you’re looking for?
I can write statically typed code that easily shapes & reshapes objects & code that fits functional or object oriented programming styles.
It's a statically typed language that feels dynamic.
Now, if I were to get a version of TS without all of JS's crutches that would be amazing.
Deno is pretty close, but it lacks on performance & is bounded in potential by JS (in some aspects).
Things like `Object.keys` irritate me because they don’t compose well. What would go wrong if TS started supporting `Object.prototype.keys`? Could even be implemented as a rewrite using `Object.keys`.
If dealing with uses after free and lack of bounds checked access in release code is still a fun factor.
> Java -?-> Go
Not at all, unless one misses Java 1.4 with loots of if/else boilerplate.
- I think you're right. C is more l'île a garbage collected C.
It is the same fallacy as C code is safe if everything was checked, while CVEs keep happening.
It’s the ideal replacement for general purpose scripting and browser work IMO. I can’t recommend it enough.
I’m sure it’ll only take a couple of years for everyone to migrate
- Just learn the language with all of its quirks
- If you are new, ignore the quirks until you are ready
Creating a new language sounds ideal, but there are a whole slew of caveats. Python tends to be recommended as a beginner language since it is reasonably easy to learn and offers considerable room for growth By the time the Next Python reached that stage, we would have accumulated a new two decades of techniques and features that would leave Next Python in a similar position to Python today. That assumes that people would even agree upon which language would serve as Next Python as a standard recommendation. One of the advantages of having so many people agreeing upon Python as a starting point is it eliminates the first hurdle novices most novices face: figuring out where to start.
As for the batteries being included, it is also a strength of Python. Choosing libraries can be difficult. That's true for the novice and it's true for anything but trivial projects. Lean standard libraries encourage fragmentation. We should have learned that from the shortcomings of C, yet many languages have followed in the same footsteps with similar results. We should have learned that large standard libraries can be useful, from the success of languages like Java and Python. Package managers don't change the degree of fragmentation, they only make it easier to deal with.
I seriously cannot think of anything I could do to exceed Python.
Does it do everything? No. But name a tool with significantly greater overall reach. Some compete, but seriously. . .
Python is the second-best language for everything.
As a happy user of clojurescript, or seeing the popularity and adoption rate of typescript, I do not count them out.
There’s no reason a new scripting language couldn’t excel in all three of those areas. But AFAIK none currently come close.
It's a personal project so I like to experiment, but it's also a CLI program that accepts command line arguments, runs, and then exits, so a 3-5 second delay _each_time_ it runs is pretty painful.
Luckily for me there's a 'single directory' option, which puts everything (uncompressed) into a folder. Snappy start because there's no decompression step, and while I like the idea of a single file .exe it turns out I don't really need that (I'm not copying the program from computer to computer).
So - thumbs up for PyInstaller!
Try including pandas with a few other popular libraries.
Suddenly you have 500MB blobs. Not very practical for passing around multiple projects.
I suppose that is not worse than Electron apps...
In the python world you have to do all the work by hand. I've literally spend time copying and pasting code out of libraries and into my code just so that my build wouldn't balloon by 100MB because I wanted to call a 100 line function.
This is an extremely unscientific comparison, because I don't feel like creating custom binaries specifically to test with. But I happen to have a copy of youtube-dl on my hard drive, and it's 1.8 MB. I'm not sure whether youtube-dl creates their binaries with PyInstaller, but youtube-dl is written in Python, and the binary is a single file that can be run without a Python installation.
I also have a copy of docker-compose, which I know for a fact is created with Pyinstaller. That one clocks in at a significantly worse 10.8 MB (so perhaps Pyinstaller is the culprit and youtube-dl is doing something unique), but that's still relatively small for a considerably complex program.
Lastly, I have a binary called "toggle-switchmate3", which I created myself some years ago. I have a set of Switchmate light switches set up in my apartment, and the best way I could find to control them from a Mac was via this Node package: https://www.npmjs.com/package/node-switchmate3. NPM's dependency mess freaks me out, so I set everything up in a virtual machine, and then created a binary with "pkg", the Node equivalent of pyinstaller.
"Toggle-switchmate3" is 36.1 MB. And it's not a standalone binary—it requires a separate "binding.node" file to be in the same directory.
Perhaps not in the general case, but in many cases it absolutely is. The problem isn't python itself but libraries. While JavaScript tends towards dozens of small libraries that do only one thing, python tends towards one library that does everything. Which is really handy in most cases, but very painful when you want to package something that just uses one of those functions.
In a concrete case I had a small script that ran a particular edge detection algorithm on an image and returned the edges in geojson format. The whole script was less than 300 lines. But the built dist weighed in at several hundred MB as it pulled in the entirety of numpy, scipy, scikit-image, fiona, shapely and rasterio, despite needing only maybe a couple of percent of the functionality of each library.
Also what is wrong in having a switch statement? (I`d like one with range cases 1<x<10..)
Accesing dicts with a struct syntax.
'Inline' C functions.
JIT, especially for loop acceleration.
_notset = object()
def foo(x=_notset):
if x is _notset:
print("foo was called as foo()") if par is None: ...
As for accessing dicts with a struct syntax, I prefer keeping dicts and objects different things (unlike Javascript).And for JIT, there's numba!
Agreed on the switch statement...
if par:
do_stuff()
Python does some really cool, if slightly unintuitive, checks for "truthiness" where 0, [], {}, false, '' and None (could be other cases too, brain's a little foggy today) all evaluate as false. This controls for: if par = None:
do_stuff()
not catching empty lists, empty dicts, etc. def myFunc(par=None):
if par:
# do whatever is needed when the parameter exists
pass
#finish processing
This allows you to pass in [], {}, None, '', or omit par all together, which will all behave as if par=None, or pass in data and use it appropriately. You can also use if not par:
pass
if you want to do the inverse.I did this before and found it really easy to integrate. The provided C API surface is really easy to integrate with. It was literally just a case of detailing my types, calling the Py runtime and then querying the results/side effects.
Having never done something like that before, i was full of trepidation - i was amazed at how easy it was.
Just off the top of my head:
- Pattern matching
- Multi-line lambdas
- Proper variable capture in lambdas and inner functions (as was fixed with the 'let' keyword vs 'var' in recent versions of JavaScript)
- Support for cyclic imports (a bad pattern in general but necessary in some cases)
- A well-defined C API for extensions that doesn't get them too entangled in the internals of CPython. This would make it possible for other implementations to reach the level of library support that CPython enjoys.
for x in ...:
and then use x outside of the loop.The fact that you can do such a thing in JavaScript is exactly why JavaScript is such a mess of a language with its globally-declared and hoisted variables.
That sort of practice has never made sense, and is not a language design that Python should follow.
Multi-line lambdas can be sort of obtained in Python by defining a progn function:
If you are new, chances are do not yet know what is a quirk and what is idiomatic.
It can be challenging and frustrating trying to follow guides or tutorials and they are all doing things differently - which is the "right" way? You have no idea as a beginner.
The one big selling point a future language could have would be inherent parallelization that uses all the 32+ cores of the developers machine, but that are as beginner-friendly as python. Such language does not exist. A dynamic, easy to use, and built from the ground up to always utilize all cores all the time without demanding that the programmer are handling side effects.
Maybe golang comes closest to that (and concurrency is messy in there), but I'm not sure if it fulfills the "beginner-friendly" criteria from the perspective of a python developer.
However, in my experience, keeping beginners away from concurrency is difficult. A lot of Go tutorials make a hard burn for it, since it's the big feature if you're already a programmer. And I've gotten (internet) yelled at for trying to suggest that concurrency is something beginners should leave until much later.
The other problem is a lot of what beginners may want to pivot into after they are done writing their "is the number higher or lower?" first terminal app isn't great for them. It's not a great game/graphical language. GUIs mostly suck. Web is awfully hard to get into nowadays, even if you try to help them narrow their focus.
Strong disagree. There is a language where concurrency is trivial and beginner-friendly. It is called POSIX shell with standard GNU tools. To run several independent commands in parallel, you print them and pipe to GNU parallel. If your concurrency has an arbitrary tree of dependencies, you print it in the form
target : dependencies ; command
and then run GNU make.Languages that make this simple stuff complicated, like Python, do so by choice, not by need.
E.g. start two long-running commands and then close the one of them depending on some later output of the other one or vice versa.
If that's not already complicated enough, we can easily add things like, execute a command A and then another other commands (B, C, D) and, only once all these are finished, run a cleanup command D. But run D always, no matter wether B, C, D fail (think of closing a database connection). And now treat this whole thing as yet another command E, that itself can be used in the same place as e.g. B or C or D before (= composition).
Shell is great for many common tasks, but I would never call it beginner-friendly, even less "trivial to use for concurrency".
Yet somehow beginners in my lab cannot get their hands off the shell and we have to politely guide them to other languages... But still, I insist that parallelism in the shell is very easy. How do you do that in Python, for example?
# convert images from jpg to png, in parallel
for i in *.jpg; do
echo convert $i ${i/jpg/png}
done | parallel
Regarding your "complicated" use cases, I must confess that I don't understand them nor their relevance. But for simple people like me without fancy needs, the simple concurrency offered by GNU parallel and GNU make is good enough.> Regarding your "complicated" use cases, I must confess that I don't understand them nor their relevance.
They are two recent examples of mine. But even if you don't see the relevance in them: if shell truly makes concurrency trivial, then the shell code should not look much more difficult then my English descriptions.
1. It's not generally taught in CS classes, and people just search up enough syntax to be able to acomplish their task.
2. A lot of it's variable expansion/substitution are remiscient of Perl.
3. Small mistakes can have huge impact (everyone knows how often rm -rf of unintended directories takes place). Just for the fun of it, I suggest everybody reads at least once the Unix Haters Handbook https://web.mit.edu/~simsong/www/ugh.pdf
If I understood your task correctly, it can be done just nicely in the shell (after all, this is what I think the shell excels at). You'll see the unpleasant side of it when dealing with function arguments and slicing values and referecing specific ones. I don't guarantee it does what you want to the letter, but just my quick interpetration of your description.
function demo() {
first=$1
last="${!#}"
$first &
wait
for f in "${@:2:$#-2}"; do
$f &
done
wait
$last
}
function first() {
sleep 5
}
function pingy() {
ping -c 8 google.com
}
function last() {
echo -----------------------------
echo done
}
function inception() {
demo first pingy pingy
}
demo first pingy pingy inception lastI'd argue that Clojure, while perhaps not the easiest language for beginners in all aspects, is both minimalistic and really fantastic for doing clean and safe concurrency.
I'd argue it replaced Perl.
Perl - December 1987
Python - December 1989
Not that the TIOBE index is perfect, but you can see what happened since 2001. Perl used to be a lot more popular for early dynamic websites and systems glue, but by 2011, Python had gotten a lot more popular in those roles.
However, their scheduler really needs speed ups, and they do run into weird data handling bottlenecks in my experience.
Making programs execute faster could be. And there using many cores is one implementation strategy among many complementary ones. But the current landscape of programming languages shows that languages focusing on execution speed and parallelism have smaller user bases.
Also, re this data interpretation of Python's killer app, this usage of Python is something fairly recent and happened after Python had already broken into mainstream usage in the industry. A lot of small and big applications have been built using it before the data and ML things got in vogue (like Youtube, Dropbox, Spotify etc at the bigger end).
Can we make that the standard and get rid of the ugly str.format(UGLINESS) syntax.
Yes please, and thank you
But otherwise, yes - make f-strings the “one obvious way to do it” and use `format` only when necessary. And get rid of the old %-formatting.
Also consider making f-strings the default: https://pyfound.blogspot.com/2020/04/all-strings-become-f-st...
`format` is still useful, particularly when working with pre-templatized strings. It's also a (relatively) new feature; Python 2 didn't have it at all.
OTOH, I wouldn't cry if Python 3.X finally removed %-formatting. `format` does everything that `%` does, with a much nicer API (especially in 3.7+).
Everytime someone uses %args inappropriately a baby seal dies.
f-strings work well in simple cases. But once the things you want to output are somewhat larger expressions, format() works much better.
Example: instead of something like
print(f'{id:<5} | {", ".join(members}:<50} | {", ".join(str(score) for score in scores):<30}')
This is much clearer IMO: print('{:<5} | {:<50} | {:<30}'.format(
id,
", ".join(members),
", ".join(str(score) for score in scores),
))
Actually, what do you mean by "ugly" and "UGLINESS" in "the ugly str.format(UGLINESS) syntax"? The UGLINESS are simply the things you want to format. Ugly is in the of the beholder of course; personally I don't really see anything ugly about format. The f-string equivalent here is much uglier and much less clear/readable to me, because the formatting and the expressions are mixed and parsing the whole thing to see what is what is more effort than it should be. all_members = ", ".join(members)
all_scores = ", ".join(map(str, scores))
print(f'{id:<5} {all_members:<50} {all_scores:<30}')No, please.
F-strings are useful for some things, but there's a good reason. to define templates other than deep in code for ease of editing them distinct from functionality (often, completely externally to code) and using str.format supports that.
If anything, I'd prefer r-strinfs as the default with both escape handling and formatting non-default options, but the status quo is acceptable and better than r-strings as the base.
I feel like Python just went through that big shift. Doubt we need a other one of those.
Also, I'd just look at Julia for some of what you're describing. It's basically going for a more focused approach with the learnings of Python in place.
We could call it Python 6.
https://pypi.org/project/flake8-simplicity/
https://github.com/wryun/flake8-simplicity/blob/master/flake...
Many seem to be happy replacing Python with Go, to get better performance, parallelism and packaging support. However, for my uses I'd much rather replace it with another high-level scripting language, even if it's still slow and single-threaded.
Kotlin solved the syntax and language warts on top of a good runtime.
For python the syntax is (mostly) good but the runtime and package management needs a rehaul.
Bolted-on classes and types annotations, and missing real lambdas isn't awesome, and lack of proper variable scoping is error-prone.
I agree that the runtime is a mess, but more in naming inconsistencies and how its organized than functionality.
Android is the only place where Kotlin actually matters.
Golang is easy to get started with tooling and packaging is good. but then the code in the wild is littered with pointers for when you wouldn't need them.
A language with a consistent design can have layers, and beginners can just do with the external bits without getting too deep initially, but with enough space to grow.
IMHO Python is a good language on that regard.
What does it matter to you if there are features in the standard library you don't use? The full python embedded distribution is only 8MB including runtime.
But they tend to get ironed out over time. Python 3.9 adds parametrized generic type hints based directly on container types, alleviating the need for a parallel type-hint type system. i.e. `dict[str, list[int]]` over `typing.Dict[str,...]`
It wasn't arcane at the time that using exceptions for decision logic, or letting loops run by assignment, rather than by creating a new scope, were not the most salient ideas.
The following Python code contains a bug:
list_of_adders = []
for x in iterator:
list_of_adders.append(lambda y: y+x)
Namely, since `x` is assigned with each iteration of the loop, rather than that a new scope is created, the `x` that the closure encloses is re-assigned with it, so all anonymous functions contain the value that `x` had in the last loop, which is almost certainly not what the programmer intended.In fact, if within the same scope, which is quite large, since Python does not like block scope, x ever be re-assigned, which is quite likely, as Python uses the same syntax for initialization and assignment, then all the closures collected in the list shall thenceon refer to the new value that x is assigned to.
These are not design choices that many other programming languages at the time made; they were bad with the knowledge of the time, and continue to be bad now. There is no justification to have loops be implemented by assignment, and not create a new scope.
In turn, implicit variable declarations (using the same syntax for initialisation and assignment) are a reasonable choice for a language that aimed to be “executable pseudocode” and that supports mixing initialisation and assignment in a single statement (e.g. `a, b, self.c = foo()`).
Having the same syntax for initialization and assignment is quite quæstionable.
It's amazing that people can program in imperative languages at all, yet it feels easy. I wonder how much trouble this causes for somebody learning how to program in a modern high level language.
I for one, think it's more likely that Python will evolve. The mathematicians and physicists, biologists, astronomers etc. that have finally gotten rid of C++/Fortran and learnt Python aren't going to change to anything with forced static typing any time soon...
- Training your entire team to use Julia instead of learning about other relevant things
- Re-writing your Python-infrastructure (or dealing with Julia to Python-interoperability, which means new employees now have to learn or know both Python and Julia)
- Replacing Jupyter and learning new, similar tools
- All employees making their favorite IDEs function well with Julia
- Figuring out how to make Julia talk to software that already has an existing Python API (Wireshark, AutoCAD, GNU Radio, ... just about everything you can think of)
Again, I’m not an academic so take what I say with a grain of salt - but I can see Julia paying dividends very very quickly in that sphere (once you’re over the admittedly steep learning curve).
- Julia is relatively easy to learn for Python people (especially the numerical people who have experience with stuff like Cython)
- The interop (both ways) is pretty great with Python
I think that package managers or not, the "batteries included" approach is great, because it leads to most of the code for useful things already available, and also helps third party packages be smaller (since they can depend on things available in the standard lib).
Imagine 3 different packages, for example, each bringing its own different json parser depedency -- as opposed to all leveraging the included json package.
That's how you get no community standards but tons of packages for the same basic things in slightly different ways, each with 20%-30% adoption.
That's also how you get 1GB node_modules folders.
That's also how you have the "leftpad" situation.
That can compile to binary, javascript and other languages?
That would be https://nim-lang.org/
"To boldly create programming languages no man has created before."
Sounds great. What made Python so beginner-friendly and readable? Most of the "let's improve Python" gang I see can't begin to answer that - by their metrics, the language must be a failure.
Beginners have the advantage of not thinking "this is the best way to do it because that's how C/C++/Java do it".
I wish Python went with static typing from the offset, and I wish it had better parallelism, but with Python you can get a library for just about anything with a simple pip install, and that's worth a great deal.
Need a WebSocket library? No problem. Need a cross-platform TUI library? No problem. Python's maturity means you can do a lot of things with little hassle. Some of the less mainstream programming languages are nowhere close to Python in this regard, even after many years.
With all these memory safe languages getting popular NSA needs more npms, not less.
Notwithstanding the various ways of doing the same thing (which sometimes goes against the zen of Python), as of Python 3.6 there's been a constant trend towards f-strings above all else (barring maintenance and legacy code), and generally beginners have no need for anything beyond f-strings. If they'd like to go into the old string formatting techniques, they're welcome to, but they're not that complex.
I don't understand how type annotations constitute a 'compromised design' - they've worked quite elegantly with Python's dynamic typing, they greatly assist linters and IDEs when you turn them off, and they can be disregarded when you don't need them, which is a far cry from the enforced typing of other languages.
And I certainly do not agree that there is a need for a "next Python". Python does a lot of things very well - it's design is clear, the design patterns are methodical, the language is well-governed, the central packaging system is reliable (and not like the insane NPM and dependencies of JavaScript), there is a distinct idiom/style consistency amongst Pythonistas, a and a large gathering of minds behind the language. Further, Python reads very well, and can be even pseudocode without being pseudocode, which makes it very much suited for beginners who can stray as far as they want to into the language when they feel ready for it.
Python is a great language for beginners, so I have no idea what you're talking about.
The Rust compiler is doing a reasonably good job on error messages. It's especially good at explaining that thing A being done here is incompatible with thing B way over there. It prints the source for both places, which is a rare feature.
A compiler that does global analysis can tell you more about what's wrong. Python, in its interpreter implementation, doesn't have the global info to tell you about global problems.
It's very disturbing from the application Dev world view where people seek longer names for reasons, but after spending time in FP/LP and math you quickly forget long names. You seek variable count reduction most the time also.
This is /especially/ true for abstract code - functions like identity, const, map.
`the trait 'Factory<_, _, _>' is not implemented for 'fn(Json<Auth>)' -> impl std::future::Future {auth}”.
What is this error saying? Can you tell? I certainly can't
It seems the type here is a function from JSON to a Future?
Given Factory means Factory, then, its saying there's no way to create an instance of that function?
It seems rust compiler team didn't write a proper error message or I cannot find meaning in this .. usually _ means 'whatever type' but <_,_,_> is useless if all types are the same whatever.
for outer_index over array1
for inner_index over array1[outer_index]
print array1[outer_index][inner_index]
Bleh.Now that I've typed that out though it kinda seems that List<Value> would be clearer, if not for the years of getting used to List<T> being the standard.
You shouldn't be talking about the meaning of T from the consumers perspective, but you should be describing it at the level of abstraction that your generic code is operating at.
I suppose clearer is a question of semantics, but to me there's not any more information conveyed by writing List<Value> vs List<T> - we already know T is a "Value" (because it has to be, due to List).
The data structure itself should provide the needed context - if the base data structure is so complex that the meaning of its generic parameters isn't obvious, that may be a case where naming them makes sense... but to me it's also a code smell of square-peg-in-round-hole.
> I suppose clearer is a question of semantics, but to me there's not any more information conveyed by writing List<Value> vs List<T> - we already know T is a "Value" (because it has to be, due to List).
Yes, I agree. However, think about functions taking 3 or more generic parameters. There's a much larger need for better information in that context
So if your code targets beginners, especially ESL people, then the verbosity has value to make that first time as easy as possible. Then it becomes noisy and weights you down.
That's an "easy" case, but in my experience, it happens all the time (though it might be especially true in C++). Should I use that "advanced"/uncommon language feature? Do I use it, but document what it does because I expect most people that will read the code not to know about it? If I'm in a part of the code base where the C embedded engineers contribute frequently, I'm going to err on the side of verbosity/clarity. On a code base with experienced C++ Dev, less so.
Result<T,E> uses T for a generic contained value and E for another generic contained value that should be an error. So far so good. The `map_err` method then uses F for the new error type because it's just next alphabetically to E and uses O for the closure it accepts as parameter because F is taken. Usually, F is used for function arguments. F and O are not just non-descriptive, having F not be the function when there's a function argument is actively misleading. Instead of `F`, something like `NEW_E` or `NEW_ERROR` would have been much easier to understand.
I would suggest something small, that you can realistically fit all in your head. I honestly believe Pascal is still an excellent choice. For something a little less low-level and more scripting-like, Lua seems nice. The JavaScript ecosystem is awkward, and there are things to criticize (no integers?) but by itself, it's a nice small language as well.
This is such a fantastic analogy. Thank you!
C++ tries to be all the paradigms, even if they're bolted on. Python is similar in that regard. Complex OO, functional, exceptions, decorators, lots of container types, iterators, generators, operator overloads... The only thing it's missing is a macro language.
Python's "batteries included" standard library stance takes it even beyond the C++ analogy in terms of sheer volume of out of the box capabilities you get.
I never experienced the "I hate Python" phase. I think I went straight from "So exciting" to "productive" phase with Python.
I reencountered Python at a data science course that was somehow mandatory for my masters in ODE numerics. It has a HUGE availability of standard and third-party packages, so you can be INSANELY productive. I'd write in Brainfuck if it was the only way to have like Pytorch and giotto-tda and networkx and fastapi in the same room.
If they would do that, then they would realize Python is as powerful as Common Lisp, Ada, C++,.... with similar doc size in pages.
And then you have macros like in macros that traverse and transform code.
Sorry, but Perl still wins there.
My first CS professor insisted the first year be done all on the whiteboard. And this wasn't back in the dark ages. It was long after every student had a personal computer on their desk. Everything was done in a low-level pseudocode somewhere between Algol and C.
She felt that computers and actual programming languages would get in the way of learning the principles. I'm not quite that hardcore. But she was on to something. I learned more from that class than any other.
https://www.python.org/dev/peps/pep-0636/
The above tutorial is based on user input but to my mind this mechanism seems equally good for teaching recursion on data structures as you would in say, ML.
When i tried to learn python i got caught up in trying to learn imports and classes and other things before i actually fully understood how stuff like variables, arrays and functions worked.
Its tiny standard library, which kind of makes it limiting, I think is a boon for learning. It forces you to remake the wheel at times. Despite not being an OOP language, I learned about OOP by trying to write my own class system in lua using metatables, hitting the limits of what I could do, and looking into languages with built in classes that had all the 'things I was missing' in my own hackish OOP attempts in lua.
As far as learning goes, not having the tools baked in forces you to learn about how they actually work when you have to remake them. It might not be efficient for people who just want to get the job done, but for learning it's definitely helpful.
Lua's also used in a bunch of 'fun' things. It's used as a scripting language in tons of games, half the time when I look up lua stuff these days it's all about roblox...which I think is big with the kids or something...it's used in fantasy consoles like the pico8 and the tic80, it can be used to script whole games with things like LOVE and the solarus engine.
Personally, I found it to be a good language overall for inspiring self-motivated learning. There's always something fun that can be accomplished with lua relatively easily.
Do you have an opinion about Common Lisp? I know that Scheme is more minimal and cleaner but since you recommend Scheme I want to know what your opinion about Common Lisp is.
I am very happy that I started with C. It has surprisingly few features compared to most languages and it gave me a good appreciation for how memory is managed at a relatively low level. The biggest downside was that it took me a long time to learn how to make anything I thought was "cool" at first (like GUIs, graphics, sounds, or networking). Some people might struggle with that.
I rarely write C code now. It's not as practical for the kinds of things I make and I have nitpicks with it just like any other language. But I don't think that's the point. Your first programming language is an instrument for learning first and foremost. Once you've become adapt at one language, it's relatively easy to pick up more.
And I think most Python developers that produce bad code do so because they try to use too many of the whiz-bang features - or overuse bad design patterns.
You can do almost anything with functions namespaced in modules - KISS.
People say scheme is hard but it is by far the easiest to teach, especially compared to Python.
Clear/Verbose -
def maxWidthOfVerticalArea(self, points: List[List[int]]) -> int:
x_coords = sorted(x for x, _ in points)
greatest_diff_so_far = 0
for i in range(len(x_coords)-1):
diff = x_coords[i+1] - x_coords[i]
if diff > greatest_diff_so_far:
greatest_diff_so_far = diff
return greatest_diff_so_far
Pythonic - def maxWidthOfVerticalArea(self, points: List[List[int]]) -> int:
xs = sorted(x for x, _ in points)
return max(x2-x1 for x1, x2 in zip(xs, xs[1:]))
I'm curious which approach is bad/worse? On the one hand, the "pythonic" approach seems brief and kind of neat and I feel clever writing it. On the other hand, it is also ~20% slower per my testing, it's less obvious what it's doing, and it would be harder to make some change to the logic (or add logging/metrics) without completely rewriting it.On the one hand, just from the reasons I wrote above, it seems to me like the first way is better and the second worse, but on the other hand, the first way is what I would write while knowing zero python features. Curious if anyone else has thoughts on this.
1 - https://leetcode.com/problems/widest-vertical-area-between-t...
I personally think either function is fine. The max finding code pattern in the long function should be familiar to most. For the Pythonic function, I don't think it's less obvious enough to matter. You have a list of stuffs and you want to find the max so you wrap it in the max function. Maybe zip(xs, xs[1:]) can take a bit to recognize but I think it's eh. For the Pythonic one, one can also write
all_diffs = [x2-x1 for x1, x2 in zip(xs, xs[1:])]
return max(all_diffs)
Using list is also markedly faster than the Pythonic generator for me, which is to be expected: ~16% faster than both.[0] https://gist.github.com/squaresmile/8dd08898851a4e19359cdb30...
This is a very personal opinion, but I do like the second one more. I find it easier to read, but maybe that's just because I'm used to that style. And maybe you're more likely to have to rewrite it for a change, but that's kind of okay since there's less code there.
On readability, here's how I'd read it out loud:
Sort all the Xes from points. Return the max of the difference between two points that are next to each other.
I find that quicker to put in my head than the equivalent parsing of the first solution, and exactly the intention of the code.
return max(xs[1:]-xs[:-1])
...using something like numpy. I wonder if APL/J has successive element operator. def maxWidthOfVerticalArea(self, points: List[List[int]]) -> int:
return np.diff(sorted(x for x, _ in points)).max() <./ ([&}. - }:) xs
[0] https://code.jsoftware.com/wiki/Vocabulary/curlyrtdot
[1] https://code.jsoftware.com/wiki/Vocabulary/curlyrtco >./-2-/\/:~ xsI’m fine with most of the rest of Python’s functional-style iterable helpers. But something about zip just doesn’t work for me.
[1,2,3,4]
[5,6,7,8]
# go down each column, yielding these in order
[1,5]
[2,6]
[3,7]
[4,8]
And then you drop ones with no pair. So zipping [1] and [2,3] makes just [1,2]. The same is true if you reverse the arguments, so [1,2] and [3] => [1,3]The example is sorta obtuse at a glance[1], but this: `zip(xs, xs[1:])` equates to this:
[1,2,3,4]
[2,3,4] # copy and drop the first element
# outputs columns
[1,2]
[2,3]
[3,4]
So it's a one-liner to make a list of of each consecutive pair of items in a list. All `zip(x, x[1:])` do the same thing regardless of the ultimate use of such a construct.But yeah, I have seen some very confusing uses of zip before sitting and thinking for a bit. TBH I think much of it is just familiarity though - after seeing a million `for (i=0;i<thing.len();i++) { ... }` I can pattern-match and figure this out easily:
for (i=0, l=thing.len(); i<l-1; i++) {
list.push([thing[i], thing[i+1]])
}
(though `i<l-1` ease may depend on font) but similarly-common functional idioms just don't slide into position as easily. Yet.[1]: I'm guessing it's the equivalent of finding the largest "gap" between a bunch of sizes of things.
xs = [1,2,3,4,5,6,...
ys = [a,b,c,d,e,f,...
[ (1,a),
(2,b),
(3,c),
(4,d),
(5,e),
|6| |f|
|7| |g|
|8| |h|
|9| |i|
|0| |j|
. .
. .
. .
]
https://kezan.eu/wp-content/uploads/2016/05/Zipper_Thumb_144...Depends on your team. If you wrote stuff in the second way you would be obstructing, adding friction to less python experienced developers but you would be minimizing the amount of code written.
It's hard to say, which is right or wrong here but the opacity of the second approach as you mention adds unpredictability.
I honestly think Dart is a very good solution from the culmination of various classical languages we've been using so far with Java and Javascript but there just doesn't seem to be any major FANG company investing in creating something more "modern" with Python.
I think it is a testament to Python's accessbility and also the depth it provides for experts as well. I guess the forced indentation is what gets to some developers but its a minor inconvenience.
when you paste this code, it's infinitely more readable out of its original context with those hints.
def max_width_of_vertical_area(points):
xs = sorted(x for x, _ in points)
return max(x2-x1 for x1, x2 in zip(xs, xs[1:]))
Just seems easier...Though I spend most my time writing Swift code, which definitely influences my preference.
Would you say this is "less readable substantially" than your example?
def max_width_of_vertical_area(points):
# type points: List of List of int
xs = sorted(x for x, _ in points)
return max(x2-x1 for x1, x2 in zip(xs, xs[1:]))Are Python type hints able to specify types like that?
My experience even before that was mostly with PyDev in eclipse. The trick back then was identifying good spots to add type-hints, afterwhich the "IDE" would take over and propagate them through the different variables and calls using static code analysis. It was surprisingly good and helped immensely with very few actual instances of types being hinted. Another one was PyCharm that would "save" or "cache" the types during debug/test runs and use them as type-hints without you explicitly having to define them.
Fancy example:
List[Dict[str, MyCustomTypeGeneric[str]]]
Which gives you a list of dictionaries with keys of type string, holding values MyCustomTypeGeneric with generic type str.
Yes, Iterable[Tuple[Number, Number]] is a valid type, though 2D points are probably Tuple[Real, Real] or just Complex, not Tuple[Number, Number].
In my vscode setup with mypy strict, pylance basic and python 3.9 though, type hints all days for me. I personally forget the arguments types like 1 second after I write the function. Maybe I'm conditioned by typed python.
Leetcode codes usually have simpler data structure and without 3rd party libraries so that's even easier to add types for.
Edit: Oh looks like Leetcode python code template has type hints
Snake case.
this-is-called “kebab case”
ThisIsCalled “Pascal Case”
def maxWidthOfVerticalArea(self, points: List[List[int]]) -> int:
xs = sorted(x for x, _ in points)
neighboring_coordinates = zip(xs, xs[1:]))
return max(right-left for left, right in neighboring_coordinates)
or even naming the width generator: def maxWidthOfVerticalArea(self, points: List[List[int]]) -> int:
xs = sorted(x for x, _ in points)
neighboring_coordinates = zip(xs, xs[1:]))
widths = (right-left for left, right in neighboring_coordinates)
return max(widths)
Same thing, just with more built in explanation. It's easy to go overboard, of course, but it's a useful go-to to make stuff more obvious. from operator import itemgetter
def maxWidthOfVerticalArea(self, points: List[List[int]]) -> int:
xs = sorted(points, key=itemgetter(0))
x_pairs = zip(xs, xs[1:])
widths = (right-left for left, right in x_pairs)
return max(widths)
NumPy also has stuff to solve this sort of thing built-in: from numpy import diff
def maxWidthOfVerticalArea(self, points: List[List[int]]) -> int:
xs = sorted(points, key=itemgetter(0))
widths = diff(xs)
return widths.max()But it doesn't do the same thing. The original code extracted the xs from the coordinate pairs, sorted; your code sorts the coordinate pairs by their x values, but doesn't extract the xs from them.
I save clever for the real mechanics of problems, for data structures, and occasionally optimization of running time if that is a factor (it often is not as much as you would think).
I eschew clever if it seems like it is just a way to pack a lot of stuff into fewer lines of code. One of the reasons that Perl attained a reputation of "write once, read never" unmaintainable code (whether or not it was justified) is a culture that cultivates "one-liners" and packing everything down into a minimum space. Our filenames in Windows no longer have to be 8.3. We are not constrained to write our code in a few kilobytes.
I programmed in the days where you might have two kilobytes in which to program. In those days, extreme terseness was a value. It is not any longer. "Cat" and "man" and "mv" are holdovers from those days. This is not a telegram where you are charged by the word. I program for total obviousness and sometimes that makes my code seem "dumb." I might do only one or two things per line. That's really fine.
Just as an example, I wrote this obnoxious web app in Perl as part of my job. At some point, some students were to take it over, but they didn't know Perl. I received an excited phone call from them at some point: they were able to understand and port my application to a language they were familiar with because I commented, I was not clever in packing, and I kept it to "one or two things per line."
zip(xs[:-1], xs[1:]) # explicit
zip(xs, xs[1:]) # implicit def maxWidthOfVerticalArea(self, points: List[List[int]]) -> int:
x_coords = sorted(x for x, _ in points)
max_diff = 0
for x1, x2 in zip(x_coords, x_coords[1:]):
max_diff = max(max_diff, x2 - x1)
return max_diffParticularly the for loop into the range of the length of the coords minus one, is difficult to wrap my head around and easy place for mistakes to sneak in.
With that being said, I have had my difficulties wrapping my head around zip, and don't have difficulties anymore, which might actually be in favor of parents point.
It has substantial pain points, the most significant in my opinion being the semantic white space that never really ever stops being a problem.
JavaScript runs in the browser, has relatively trivial syntax, no semantic white space, C-like, a superior and more useful GUI, etc.
I see no reason to teach Python per se unless people request it.
[1] (You should be indenting to indicate your block structure anyway. A lot of beginners I've seen get their indents mixed up with the actual block structure. Not so with Python: The code runs like how it looks.)
Personally I think it's easier to spot mess-ups with indents. Some people think braces are easier. I won't fight with those people today :-).
But I don't think randomly cut&pasting code anywhere is a good idea. If you do paste code, you really should understand what the code is doing first.
The real key is: treat excess indentation and nesting as a code smell. Python should aim for 5 tabs deep max, imho. Anything else should be refactored into functions.
Part of me wants to forbid all "dumb" text editors for introductory programming courses and make everyone use an AST-based one that only allows you to create syntactically correct programs. Unfortunately there's zero chance of that happening any time soon...
Here's a weird thing that seems to work (especially while learning): Instead of copy-pasting code, type it into your program by hand. For some reason this helps a lot when trying to understand or debug the code that you are entering.
This works equally for those of us who started learning using BASIC on 8-bitters, all the way to Python, Java, or odd things like Siemens SCL.
Wrt editors: the times I've taught people, I actually went completely the other way: requiring the first few programs to be written in notepad or nano (depending on OS) . This tends to take the magic out of what the IDE is doing, and makes everything after it much easier.
Both of the above would seem to be relatively time-consuming. But oddly enough in practice they can save more time than they consume.
I also don’t give homework. If you want to learn on your own, you can, but homework is a massive crutch that I don’t think benefits most people.
Have you taught a similar crowd any other language and gotten a different experience?
Because what you describe sounds like the students in my introductory programming class, which was in C++. Sure, they didn't have whitespace issues, but did demonstrate a similar lack in rigor, and giving up easily.
The equivalent in an introductory C/C++ class:
"I put a newline, why do you care if I put a semicolon?"
At some point, students have to accept the quirks of any language's syntax. It's OK to have an opinion and hate it, but whitespace complaints are mostly a preference issue.
(Every time I switch from Python to a language requiring semicolons, it always feels like I'm hitting endless speed bumps.)
While Python may not be a beginner language, nor is Java/C/C++, in my opinion - and for people completely new to programming, those have a steeper learning curve than Python (the for loops are just hideous). These were the standard introductory languages in college before Python took over. I'm sure better teaching languages exist, and I'm also sure JS is not one of them ;-)
Another good candidate is golang.
I’m going to think on that one a bit more.
If your goal is understanding data structures, algorithms, etc, then C is hideous. Explaining function prototypes, include headers, very unfriendly I/O, and I already mentioned the horrible syntax for for loops.
There's a reason most of the data structures/algorithms were in a second course at my university: It's because it took most of one semester for students to get a handle on the very basics of C syntax.
First, is that in no other text form, does white-space change meaning such that the text becomes "unreadable" (sure your docs may be formatted a little weirdly, but hey someone can still read it). Simple python is close enough to prose that people get confused.
Second, is that they haven't learnt to grok compiler messages - the program either works or doesn't work. Coupled with number 1, it basically means they can't /see/ any issues or fix them.
And ... very interesting... what are the pain points when interacting with compiler/interpreter messages, in your experience? Are they introduced early on?
I'm not entirely sure - but the terseness of the message and the out of the way location meant that the students... mostly ignored the errors. I think having a pedagogic IDE [1] which would /massive/ highlighting and really verbose errors may have helped; but that's entirely my speculation.
[1] Example of a pedagogic IDE which has arrows: https://i.stack.imgur.com/CwKQG.png
JavaScript syntax is outright bizarre compared to Python. Care to share your slides teaching the semicolon rules, four or so different scopings, the damn "new", type coercions and so on to learners?
Javascript has mostly nicer semantics, but buried deep in ugly pile of mess. And CPython is a disgrace.
As for teaching JavaScript’s pain points... that’s not really how I operate. I’d rather they know the general rules and come across edge-cases when they’re in a position to solve them, rather than overload them with information. Automatic semi-colon insertion is powerful enough to get you through several large-scale projects, so there’s essentially no point to discuss it prematurely as anything but a curiosity, “this could be a gotcha, so keep your code clean”.
Finally, comparing the error linters in VSC for Python versus javascript, especially if you //@ts-check... I think JavaScript actually does a better job.
I have hard time understanding how changing the indent has somehow more overhead. Even with dead-simple automation where the current indentation level is kept for a new line the blocking is literally controlled with just backspace, tab and enter (space indenters and their enablers shall rot in hell).
Braces are also awkward to type with many keyboard layouts. Once you get used to it it's not much of a problem, but for beginners in can be an annoyance distracting from the actual programming.
Javascript quirks are so prevalent that you're bound to encounter them even in the very beginning. E.g. in comparison operators or accidentally assigning to global scope.
I don't use linters and haven't really felt the need. Heavy use of linters tends to be caused by bad language design and/or obsessing over pointless cosmetics.
You should really consider using linters as a teaching aid. They help a lot, and would indeed catch the problem you noted about js.
Really? At one point I was looking into using a linter program in my Intro-To-Programming-With-JavaScript and then realized that it didn't really catch any syntax errors because there were so few.
For example - you might call a function like this:
x = myFunction();
But what if you leave off the (), which is an easy to make, beginner/novice type mistake. Then you get this, _which is still valid JS_:
x = myFunction;
What if you leave out parameters that your function needs? What if you include extra parameters? What if the parameter types that you're expecting don't line up with ones that are provided (perhaps because you left out / added in an argument?)?
On the one hand I get it - JS is a loosely typed language so it doesn't do a lot of syntax checking at code-writing-time/"compile-time"/linting-time, but on the other hand there is a _ton_ of easy to make novice errors that are actually valid JS code.
I'm not saying that Python is a better choice for beginners, I'm just not convinced that JS's relative lack of syntax-based limits is a great choice either :)
On the other hand, your example is valid Typescript, although if you use attempt `x + 1` then Typescript will yell at you for incompatible types.
Unfortunately your example is also a problem in Python, if not worse:
def foo() -> int:
return 42
# valid
x: int = foo()
# also valid
x: int = foo
Why is this valid?! Well, Python doesn't actually check your type annotations, you have to choose and use a type-checker (example: mypy). There is no default type checker for Python, and invalid types are silently ignored by the interpreter.Python's whitespace rules are a minor nuisance to some, but at least there is consensus among Python devs on how to do something as fundamental as iterating over a list.
I write JavaScript all the time. It has improved a lot over the last decade. But I could never teach it to a beginner.
Don't get me wrong, though. I wouldn't teach Python to a beginner either.
If your beginners prefer C like syntax then I doubt they are really beginners at all.
Incidentally, Ruby has a similar problem for self-learners.
As someone not really familiar with python besides using it instead of one off bash scripts, I have the same feeling about using it. When is python to appropriate language to pick? Not high performance, not safe, does not run in the browser, not embed friendly, no unique features. There are more mature and bigger ecosystem out there with better tooling and there is the whole python 2 vs python 3 thing.
Yet I see so many python positions advertised, that I consider picking it up.
Numpy, scipy, matplotlib, flask, django, tensorflow, ... all the way down to tiny packages like emcee makes it an extremely compelling ecosystem to develop software in.
For almost every science or engineering domain, python has some of the best in class libraries available (either native or as bindings to the standard C libraries everybody uses). It is more likely than not a plug in or scripting language for the engineering desktop application you use. It will let you do everything from interactive data analysis to web development, to scripting and devops, to cutting edge ML research in the same language using mature and battle tested tools. This is extra nice if you are combining many different domains, like doing Machine Learning and Computer Vision on GIS data and presenting the results on an interactive web site.
Especially if you're ambition in life isn't to be a professional programmer, but rather a professional that uses programming to do his job, then learning just one language is very enticing and python is probably the language that is most likely do have everything you need to get the job done, no matter what that job might be.
Shell scripting, e.g. dev ops? Ruby for me, Perl for complex regular expressions.
Web development? This depends.
High performance environment? Golang, C.
Basically, the care where Python is called for is the scenario where it offers a library you absolutely need, not anywhere it’s definitely the best language for the job, because it rarely is.
Python is the biggest victim of its own success. There have been warts in Python since the beginning, but they mostly only look like warts in retrospect because of how much Python has shifted the conversation about what a language _could_ be.
I hope someday something truly better along all the relevant axes will replace Python. But Python has maximized utility along so many of those axes that it's an (observably) uphill battle for everybody who is currently trying.
https://mobile.twitter.com/reuvenmlerner/status/129031712499...
Guess you're just a better programmer. I've run into many in JavaScript and Python.
About the only thing I can think of is that I still routinely switch to C for Arduino projects so I am cognizant of things needing to be the right type and don’t rely on automatic casting like you get in PHP and JS.
How do you know what the argument “details” should be?
The function documentation says “takes the query details” ... so people sit down in the repl and just screw around with the functions to try to figure out what they do, or search for examples of how they’re used.
with type hints, this discovery process for other programmers was significantly quicker and on boarding was faster.
I mean, sure, just write better docstrings, but type hints can’t get out of date, because it’s a type checking error.
Maybe a better solution is rust style “compiled doc strings” so the documentation can’t be wrong, or rust style inline unit tests that show examples of how to use functions... but python has neither.
It’s been my experience that type hints for your own code... eh. But if you’re working in a team, they’re valuable.
charge_customer(order_details: dict)
That fact that it’s a dict is the least of my worries. I need to know what goes into it, for which I need to either read the docs or the code. So you try to organize it more and avoid using something like a dict of order details. Instead you create an order object that has methods like add_item(id, qty). Can you guess what those are or deduce it quickly by looking at docs or the implementation of the method? Most likely. I’m not saying that type hints won’t help. But as far as just type checking at compile time they only really work as a very obtuse tool, and at runtime they are a very feature-barren form of contracts.You can do it in other ways, sure... but I don’t accept that you can argue type hints have no worth.
... if they are the correct solution for every case? If they are worth the (honestly fairly trivial) effort to write and maintain?
Those are fair questions.
The question is, if you’re or using type hints what are you using instead?
...I how the answer isn’t “nothing”, because that just means you not using a tool because you don’t like it, not because you have a good reason.
I can't personally guess the type of the `id` argument to the hypothetical `add_item(id, qty)` function, but I would guess that the source code for that function would look like
def add_item(self, id, qty):
self._items.add(id, qty)
I would also note that python type hints can be charge_customer(order_details: Dict[Product, int])
which is significantly more helpful than just knowing it's a dict.I also use it a lot at boundaries where the modality changes, eg going from local data structures to RPC, where the data shape is the same, but there is io and fault tolerance to deal with.
Over time, this has a very noticable impact on development speed, and in a very painful way for the individual developers who need to spending your time tracing the various call paths in unrelated code and build up a mental model of the involved types every time they want to do a nontrivial change, and then deal with the fallout of unintentional bugs due to missed code paths for an unpredictable amount of time as they are discovered.
So when there is a solution that can completely eliminate this class of bugs in an automated way, this sounds like a very appealing feature.
It's basically like they work by accident. It's not documented what goes in or goes out, so someone throws some data into a function and if it doesn't break then consider it success. And any future person that has to make a change has to untangle that whole mess.
For example I'm sure you've had runtime production errors where you tried to call a method on a null object many times. That is the kind of thing last generation type systems couldn't help you with, and new systems do.
It's the one thing that I think really holds back go from being phenomenal (I still love it), and I hope generics help with that.
Another big benefit is how it makes your code self-documenting -- and makes that self-documentation self-enforcing. If you are making an API for consumption, it's dead simple to make it very clear how it's structured, and to set & enforce contracts for its usage.
For me, in general it is more about its power to ease the cognitive load associated with coding. Having to constantly look up documentation to see what the types of arguments are and in what order they need passed brings me out of flow. When I don't have to think about that, I can spend more time focused on the problem at hand. That doesn't mean I can't program without them; I have to do a fair amount of Vue stuff at work and I make it work despite not being a front end guy. But my preference is always for static typing.
Same here. The arguments for it seem to be:
- It allows you to find bugs in your code without running it. I’ve concluded that my workflow must be different from people who make this claim - I never write code without testing it. This is more comprehensive than relying on a type checker, because it finds all kinds of errors, not just type errors.
- It’s a form of documentation of function parameter and return types. This is better served by comments, because type hints are usually inaccurate in a duck-typed language like Python. For example, I see hints like `def twice(x: int) -> int: return x+x`. The correct type for a function like that isn’t `int`, it’s something like `addable`.
If you know that x is only ever an int then you can safely change the implementation to `return 2 * x`. Sometimes constraints give you extra possibilities.
But perhaps that only makes sense for some functions. Probably not twice().
Neither do I. IDE integrated typecheckoing still finds the kinds of bugs typing can find faster than IDE integrated unittesting, and often as they are being typed.
> This is more comprehensive than relying on a type checker, because it finds all kinds of errors, not just type errors.
It's still slower for the very broad class of errors a typechecker can highlight than static analysis, and unless you are very good at writing tests, far less comprehensive in that subcategory.
> It’s a form of documentation of function parameter and return types. This is better served by comments, because type hints are usually inaccurate in a duck-typed language like Python.
Conversely, it's better served by analytically confirmed annotations, because comments are usually inaccurate in most languages.
> For example, I see hints like `def twice(x: int) -> int: return x+x`. The correct type for a function like that isn’t `int`, it’s something like `addable`.
It's `int` if that's the promise I want to make to users that they can rely on and that I will fix bugs against and that I will adhere to in future changes that aren't SemVer major. That the implementation can supporting something broader is a private detail, not part of the API presented. It might use an optimized routine that relies on implementation details of Python ints tomorrow and just be using + today because correctness and delivery schedule beats optimization in this case. In fact, that possibility would be the only reason to a abstract something a simple as application of a simple binary operator
OTOH, I frequently see argument or return value specs in comments that include types that are plain wrong, not subsets of what the underlying code supports.
There are many, many things that can be expressed with types... depending on the type system. In Haskell, when you look at a function type, you instantly know whether it returns an optional value (a Maybe), or if it has side effects (IO), etc. You can also tell how general the function is, by how abstract its parameters are.
An example of something that becomes possible with a rich type system: https://hoogle.haskell.org/
(In statically typed languages with implicit nullability, nulls create the same problem.)
Basically, explicit contracts are Good, and types are a subset of explicit contracts that are more easily enforceable than most.
x = list[1, 2, 3, 4]
I assume yet another new bit of python syntax thats unguessable what it means...
Typical use would look more like this:
x: list[int] = []
i.e. x is a list of integers that starts out empty.It doesn't automatically do anything at runtime, it's basically a glorified comment for tools and libraries to use. So that does make it harder to figure out what it is.
Or it could work with a custom type with overridden operators through __getitem__.
It's a stretch to call it "completely normal" though I believe you're correct in a strict sense: you could always construct the rest of your program such that it would contain that line and still compile. It would be extremely bad style.
Basically they alias all of the old builtins like list to typing.List etc. (Or maybe one should say the goal is to un-alias the alternative type system in typing-module and only use the original builtins).
It can be useful when you for example want to create a type alias like UserList = typing.List[User], which was possible even before, the change is that it now affects the old builtin also, so things that were previously syntax errors are now valid type aliases. Usually such alias assignements are more useful once you have more complex generics with nested dicts and stuff.
>>> print range(10)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
Integer math works exactly the way you would expect with no horrible surprises at all: >>> print [x * 3 for x in range(10)]
[0, 3, 6, 9, 12, 15, 18, 21, 24, 27]
>>> print [x / 3 for x in range(10)]
[0, 0, 0, 1, 1, 1, 2, 2, 2, 3]
Python is great for little one-off tasks; say you want a color half the brightness of #308cfb >>> hex(0x30 / 2)
'0x18'
>>> hex(0x8c / 2)
'0x46'
>>> hex(0xfb / 2)
'0x7d'
The built-in support for dictionaries and JSON parsing make data conversion easy: >>> import json
>>> json.dumps({'foo': 42, 'bar': 132}.values())
'[42, 132]'
If there's one thing I love about Python, it's how easy and consistent it is. It sure is great that we've spent the last decade teaching Python to every scientist, academic, and hobbyist.If there are two things I love about Python, it's that and the reliable, well-supported Python package manager.
>>> print [x / 3 for x in range(10)]
[0, 0, 0, 1, 1, 1, 2, 2, 2, 3]
Wont that print floats nowadays?Half of them are about functions like range() and .values() becoming lazy instead of returning simple lists. I think this is a genuine blow to ease of use, though it does get rid of performance pitfalls.
The other half are about / always doing float division. But I think that's actually more intuitive for people who aren't already used to other programming languages, and it's much more predictable given that Python is dynamically typed and floats and ints sometimes get mixed up. It's also not awkward to work around, you can just write // instead of /. (Working around the other issue requires wrapping list() around things, which gets ugly very fast.)
>>> print(range(10))
range(0, 10)
>>>I was so upset when Boo was ditched from Unity, I loved it so much!
I appreciate the ability to format things on the next line without worry about how the system will handle it. It's more of a formatting edge case but it comes up enough to be useful.
In the end, I feel like it doesn't matter to me nearly as much as other syntax choices in languages, as I've done a lot of Python with no braces and a lot of other stuff with them. I don't even notice anymore (although maybe counterintuitively I find braces a bit more readable now).
I would humbly suggest that maybe the name "friendly traceback" is not the most beginner-friendly thing, since if you are a beginner programmer you are perhaps not 100% sure what a "traceback" is, and why you would benefit from friendlier tracebacks.
I don't see type annotations as adding a fundamental difficulty to the sorts of error reporting described in the article, just something which makes it a bit more challenging to achieve.
Python feels like a mess by comparison. As a computer science type myself, my tribe’s provincialism towards “languages like C”, like Python, just gets old.
That level of debug information is useful to "advanced" users. Sometimes the hardest things to debug are brain fart moments. also when a library raises an exception that you've never seen before, extra context is useful.
I frankly couldn't give a shit about :=, but I would give money for GIL-less multithreading.
Thank you for yet another example of why there’s really no such thing as an “optional” feature.
One is that traditionally, there was a clear split between "system languages" which were usually fast, compiled languages that were relatively verbose, not very comfortable, and comparatively unsafe -- and "scripting languages", which were dynamically typed, dynamic memory management, often interpreted, offered more data types and facilities, but were slower.
C belonged clearly to the first group and shell scripts, Perl and Python to the second.
But the gap between these two groups has been shrinking, as languages are overall converging: Java uses dynamic memory management, Go has a very fast compiler, C++, Scala and Rust have iterators, type inference and such. On the other hand, script-like languages added type annotations, got generally faster, and so on. Much of this is due to better and better compilers.
Python stands out in this landscape like a sore thumb - its performance did not profit much from better compilers.
There is another axis which is the range between direct low-level manipulation of bits and bytes and symbolic computation and functional languages. Lisps, OCaml, Scala and Haskell are from the family tree of symbolic computation. Traditionally, these languages were heavy-weights and slow compared to the system languages, but they also have seen enormous progress from better compilers - Common Lisp implementations like SBCL can now produce code which is almost as fast as C. As a consequence, there is also a convergence of general languages with "symbolic" features like first-class functions, type inference, list comprehensions, and so on.
The third observation which I find very interesting is how much Python and modern Lisps/Schemes do have in common. If one has a close look, the extend of this convergence is really astonishing.
Here are some things that modern Lisps like SBCL, Schemes and functional languages on the one hand side, and Python3 do have in common:
* a Read-Eval-Print Loop (REPL)
* strong dynamic typing
* automatic memory management
* memory safety
* exceptions
* a wide choice of built-in data types: lists, strings, vectors, arrays, dictionaries / hash maps, tuples, sets
* keyword arguments and optional arguments in functions
* handling of names in scopes and names spaces
* closures and lambda functions
* list comprehensions
* pattern matching (limited support for tuples and lists in Python)
* Unicode strings
* arbitrarily long integers
* complex numbers
* rational numbers
* number type are part of a hierarchical type hierarchy (numeric tower)
* empty sequences, containers and strings are logically false
* support for threads (but no real parallelism in Python)
* low-level bit operations (a bit limited in Python)
* easy way to call into C code
* type annotations
* if ... else can be used as an expression
* string formatting is a mini language
* hexadecimal, octal and binary literals
* standard functions for functional programming like map and filter
* support for OOP (e.g. by the Common Lisp Object System)
* support for asynchronous execution
The few remaining distinctions between Lisps and Python are:
1. Lisps use parentheses to determine scope, while Python uses indentation and white space.
2. Lisps usually compile either to native code or to JIT-compiled byte code, while standard Python uses interpreted byte code.
3. Python does not support true parallel execution within the same process.
4. Lisps have of course the typical macro system which, for example, allows to define new control constructs, while Python does not have macros.
5. Lisps and Schemes have with conditions, restarts, and continuations some unique way to handle errors and manipulate the control flow (see http://www.gigamonkeys.com/book/beyond-exception-handling-co... )
So, what I find really interesting is that for example Common Lisp, which was standardized first in 1984, has so many features in common with more recent languages - and still much better performance than python:
https://benchmarksgame-team.pages.debian.net/benchmarksgame/...
https://benchmarksgame-team.pages.debian.net/benchmarksgame/...
https://benchmarksgame-team.pages.debian.net/benchmarksgame/...
https://benchmarksgame-team.pages.debian.net/benchmarksgame/...
In fact I think Javascript fits the title better. Python3 is still simple and advanced enough over Python 2, I just don't really agree with the author here.
The only thing I can dream about is some type of typescript like version of Python with good old-fashioned type checking. I prefer C# and Flutter only because I really need types when my applications get larger.
That was python 2...
Python 3 is "growing up" and losing the simplicity and ease of use for complex hard to understand power-user features... It's the lifecycle of any language - see C++ which is 20 years ahead on the same curve...
It handles allocating and deallocating memory for you, keeping data and code together, a nicer way to write to the console, and other basic things.
I think you have to look at it with 40-year-ago eyes to see it...