How to write X in both Python 3 and JavaScript

https://sayazamurai.github.io/python-vs-javascript/

by chibicode • 8 years ago

178 78 8 years ago

sayazamurai.github.io

sayazamurai• 8 years ago

Creator here! Let me know if you have any suggestions.

sharemywin• 8 years ago

Very cool reference.

zitterbewegung• 8 years ago

Add Python 2 and or another language that has a static type system like C.

laumars2• 8 years ago

I think anyone who hasn't learned to do X in Python already really should be better off learning it in Python 3 rather than a version of the language which is in the process of deprecation.

nanna2• 8 years ago

Either you forgot to mention that this is a personal todo, or you're trolling the author?

laumars2• 8 years ago

I genuinely love the design of the page. It has personality without compromising readability. This is something a lot of people struggle to get right.

Sir_Cmpwn• 8 years ago

Consider renaming to "How to write $X in both Python 3 and JavaScript" to avoid the confusion with X11 that others have pointed out? Nice article!

mschuetz• 8 years ago

Nice list.

Perhabs just personal preference but I'd use

    for(let element of someList){
    	console.log(element);
    }

instead of

    someList.forEach(element => {
      console.log(element)
    })

for...of is easier to read and recognize as a loop construct at first glance, and as far as I recall it's also faster nowadays since the body of the loop is inline, whereas forEach requires the runtime to deal with a function object.

tormeh• 8 years ago

Makes me wonder if maybe the syntax for mapping, folding and other collection operations should have a similar syntax to for instead of the current method-style syntax popular in most modern languages.

tuesdayrain• 8 years ago

Personally I find the method-style syntax significantly more readable.

jsh7• 8 years ago

You can also ‘return’ the outer function from within a ‘for...of’ which is pretty useful imo.

FlyingLawnmower• 8 years ago

Thanks for the site! Do you have thoughts on removing all the print/console.logs calls on every line? It feels like there's a lot of visual noise there, that can still be met with the comments showing state/output.

plopz• 8 years ago

I might suggest replacing javascript's parseInt() with Number()

fogetti2• 8 years ago

I really like the page. I really enjoyed going through the list. One suggestion would be to add python/javascript generator functions to the list.

settler4• 8 years ago

It would be nice to have a sectioin with things that work differently in both languages. For example in python `if []:` evaluates to False while in javascript `if ([]) {` evaluates to True.

andyfleming3• 8 years ago

Instead of...

    Object.entries(newDict).forEach(element => {
      console.log(`${element[0]} ${element[1]}`)
    })

... you could write ...

    for (const key in newDict) {
      console.log(`${key} ${newDict[key]}`)
    }

... or ...

    for (const [key, value] of Object.entries(newDict)) {
      console.log(`${key} ${value}`)
    }

floatrock• 8 years ago

Truthiness!

Although this is a case where idiomatic python is different from idiomatic js.

In js:

  // same:
  !! ""   // false
  !! 0    // false
  !! 1    // true
  !! null // false  

  // different:
  !! {}  // true
  !! []  // true

while in python:

  # same:
  not not ""    # False
  not not 0     # False
  not not 1     # True
  not not None  # False
  
  # different:
  not not {}       # False
  not not []       # False
  not not tuple()  # False

armandososa• 8 years ago

First: congratulations, this is very well done.

Second: I don't like seeing JavaScript code without semicolons. Maybe I am old, but it makes me nervous.

thomasfedb• 8 years ago

A weird reference imo. Perhaps useful to build as a learning experience but I wouldn't expect who needs if/else included in a cheat sheet to be ready to learn to languages.

fabiomaia2• 8 years ago

The value is in finding what is the most idiomatic way to do something in either language. For example if you're coming from Python and you're used to sum() it is useful to check this reference for the most idiomatic way to do it in JavaScript before doing it by hand with anonymous functions and reduce or looping through the list (as is the case unfortunately).

LyndsySimon• 8 years ago

Agreed. The value isn’t in it being a tutorial, it’s in it being a quick overview of a language’s idioms as they apply to common tasks.

marsrover• 8 years ago

When I read the headline I was expecting the X windowing system. When I clicked the article and saw “junior programmer” I thought this is about to be impressive.

Cool site :P

aninteger• 8 years ago

How to write using X in both languages:

Python: https://github.com/python-xlib/python-xlib

Node.js: https://github.com/sidorares/node-x11

de_Selby• 8 years ago

This is what I actually thought the article was going to be about!

ISL• 8 years ago

This what I expected from the title.

donio2• 8 years ago

A couple more native X11 client implementations:

Common Lisp: https://github.com/sharplispers/clx

Go: https://github.com/BurntSushi/xgb

Any others?

(Looking for implementations of the X11 protocol in $LANGUAGE, not bindings to the C Xlib)

donio2• 8 years ago

One more that I use:

Emacs Lisp: https://github.com/ch11ng/xelb

52-6F-625• 8 years ago

Haha, I also expected this.

Now I'm kind of glad you responded in kind because I'd seen python-xlib but not the node one. That sounds like a bit of fun and punishment at the same time.

bateller• 8 years ago

At least I wasn't the only one lol

fabiomaia2• 8 years ago

Very cool! Reminds me of http://youmightnotneedjquery.com/

I particularly enjoyed seeing that you used snake case in Python and camel case in JavaScript. Great attention to detail.

mvilim• 8 years ago

http://hyperpolyglot.org/ is a great website with a similar idea.

neillyons• 8 years ago

https://learnxinyminutes.com/ is another website with a similar aim.

agumonkey• 8 years ago

I quite like this as super thin intro. So far I always fonud it motivating enough to jump into deeper articles/books.

ChrisSD• 8 years ago

As someone who is often switching languages, I find these sorts of cheatsheets useful.

I know all the syntax in them but I'll be damned if I can ever remember which language uses which until I've settled back in to things.

chooseaname• 8 years ago

Me too. On any given day, I can be using any of a half dozen languages (C#, powershell, javascript, bash, perl, python, c++, java - our codebase is all over the place). It gets hard to keep the syntax straight on all of them.

abstractbeliefs• 8 years ago

You might find Rosetta Code to be useful - it's a wiki site with hundreds of examples, all with solutions in dozens of languages for comparison.

ikewise, I felt a little let down. On the flipside, it's an excellent opportunity to bring Rosetta Code to people's attention - a wiki with hundreds of example problems, each solved in many languages for comparison!

https://www.rosettacode.org/wiki/Rosetta_Code

I find it invaluable in that sort of mid-learning level of a new language, where I have the syntax sorted, but I need lots of programs small enough to hold in my head, but also large enough to show off all the features, to learn and read. Here's Dijkstra, for example: https://www.rosettacode.org/wiki/Dijkstra%27s_algorithm

derimagia• 8 years ago

My go-to site is usually https://learnxinyminutes.com/

ingen0s• 8 years ago

Excellent educational tool - will be passing this around to colleagues who need it. Thanks!

nanna2• 8 years ago

Same here!

enitihas• 8 years ago

I was expecting to see a leftpad comparison too :D

sheikheddy• 8 years ago

I love it! Reminds me of https://www.interviewbit.com

ramses0• 8 years ago

No mention of http://rosettacode.org, tsk tsk. (specifically: http://rosettacode.org/wiki/Category:Programming_Tasks)

arendtio• 8 years ago

Hehe, I didn't know that but the page reminded me of of the Arch Linux Rosetta Stone page[1] instantly ;-)

[1] https://wiki.archlinux.org/index.php/Pacman/Rosetta

alyandon• 8 years ago

Sort example doesn't take into account Javascript does lexicographical sorting?

javascript:

  someList = [ 40, 2, 1, 3, 7, 99]
  someList.sort()
  Array(6) [ 1, 2, 3, 40, 7, 99 ]

python:

  someList = [ 40, 2, 1, 3, 7, 99]
  sorted(someList)
  [1, 2, 3, 7, 40, 99]

fogetti2• 8 years ago

That's a good point. Although there is another sorting example which is using the correct format. But yes, you are indeed right.

52-6F-625• 8 years ago

It depends on whether or not you pass it a basic comparator function, eg:

    someArray.sort((a,b) => a - b);

But yeah the example would have needed this for the less complex example as well to be accurate.

orf• 8 years ago

Shouldn't that be `a < b`?

Too2• 8 years ago

Common mistake when writing a sorting function, a-b is not safe in languages with integer overflow because it will give you incorrect sorting for large numbers. In javascript where everything is double you're probably safe from that kind of error but maybe NaN can give you problems instead?

kbd• 8 years ago

Oh gosh. TIL.

Edit: I'm actually truly grateful, I'm sure this bit of knowledge saved me some of my hair in the future.

slx26• 8 years ago

Your comment led me to discover https://www.reddit.com/r/softwaregore and reaffirm myself that I should stay away from javascript for as long as I can

FridgeSeal• 8 years ago

I swear this language gets worse every time I learn something new about it.

combatentropy• 8 years ago

To me this seems like a bug, or at best an incomplete implementation. Let's fix it in the next version of JavaScript, okay? I suppose someone's code will break, but was it worth preserving?

basilgohar• 8 years ago

I thought this was going to be a polyglot[1] demonstration of writing code for X Windows. However, I was not disappointed in what I found!

[1] https://en.wikipedia.org/wiki/Polyglot_(computing)

feniv• 8 years ago

Reminds me of this OneLang HN post from several months ago - https://news.ycombinator.com/item?id=16415051

It's an IDE that lets you code simultaneously in several different languages https://ide.onelang.io/

dkonieczek• 8 years ago

Do people actually use cheat sheets like this? IMO, the first stackoverflow result in google is generally what I'm looking for and quicker - especially for common things and common languages such as the things on this page. Even if you have the page bookmarked, you still need to find/search/scroll for the specific thing you're looking for. Also, with Alfred you can google anything even quicker by not having to cmd+tab to the browser.

cirgue• 8 years ago

Maybe not as a reference, but it's certainly helpful to browse if you're going from one language to another (I know python and I'm learning Javascript, this probably saved me a few google searches)

andyfleming3• 8 years ago

In the past I've enjoyed using cheatsheets to get a quick feel for the syntax of a language. It's nice to see a less familiar language next to a more familiar one.

jamesgeck0• 8 years ago

I used a resource similar to this to get started with Javascript almost a decade ago. Reading through the examples start to finish is a decent intro to the basics.

undershirt• 8 years ago

this is very good. i had it in my head that there was no "extend" function in JS, and didn't realize "push(...array)" was possible. thank you for the super detailed guide

aavotins• 8 years ago

I had such high hopes when I opened the arsenal. I anticipated it would an article of how to write code that's both JavaScript and Python syntactically correct.

tobiasz-cudnik• 8 years ago

Reminds me of PLEAC - Perl Cookbook translated to >10 langs http://pleac.sourceforge.net

anticensor• 8 years ago

I expected a Python/JS polyglot :)

nayuki• 8 years ago

When I publish code about algorithms and data structures to my web site, I usually offer multiple language versions. Why? Because understanding the computer science theory and math proofs is a big effort. Writing and debugging my first implementation in any language is a big effort. But porting that code to a bunch of languages is comparatively easy and is almost a thoughtless mechanical process.

another-cuppa• 8 years ago

What's the point of having print or console.log around everything? Just have one box with "print to standard output" and those two at the top.

tracker1• 8 years ago

FizzBuzz example isn't correct

Too2• 8 years ago

Impressive to see almost all JS examples being as short as the python ones. Python is normally valued for being short and concise but modern JS is really catching up here.

How to write X in both Python 3 and JavaScript

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