#difference between python and java languages

[blake447]

Okay so like, i need to share this again because as of now no one has indicated to me that they understand just how absurd this is.

https://youtu.be/J7IKKzzApg8?si=04tTU-EeDF-A09mL

This is a zoom of a 41 iteration dragon curve. That's right 41 iterations. Why? Because i can :D Fun fact usually generating a dragon curve the memory requirement doubles each iteration, because you are copying and rotating the current curve. Double the segments, at best without any clever optimization its O(2^x)

So how hard is it to make say, 20 iterations? It was a long, long time ago, like 10 years, i followed an article that said you kind of have to write it in c so its more performant because 20 iterations on their machine took 20 minutes. 2^20 is going to be in the low one-millions range.

Now lets be more optimistic. Lets say computation time on a single cpu core has sped up 20 times, so you can generate a 20 iteration curve in 1 minute.

So 21 would take af least 2 minutes.

Now our scaling looks something more like 1m*2^(x-20). If we plug 21 more iterations to bring us up to 41, well we already know 2^20 is about one million, so this would be 2 million minutes or a bit under 2 years.

But guess what. This is rendering in real time. It would be incorrect to say that it generates the curve over 60 times per second, but it generates the visible part of the curve.

So what clever optimization trick gets me over a 120 million times speed boost at 41 iterations? Parallelization. See, this isnt just any dragon curve you see in c or java or python.

Nah girlie's running on the unity engines CG/HLSL shader language. The trick is to instead of generating the curve, and placing the segments with that info, we repeat the process that forms the dragon curve backwards. A dragon curve starts with a single segment, and it has 1 mid point. When folded, it turns into 2, and has 2 midpoints.

So what we do is we test every pixel, find its closest hypothetical midpoint, and then perform the transformation backwards. Since they originate from one segment, and this method ends up halvening the midpoints each time by merging them on top each other. These means after your desired number of iterations, we can simply check to see if the pixel we were on collapsed back into a specific midpoint.

Making midpoints integers an example would be the line segment from (0,0) to (0,2). Well then im that case the midpoint would be (0,1).

This scaling even allows us to keep track of everything via modulo operations. The vector math ends up working out so that most the time you're rotating and scaling, but the net displacement from the two is a fixed size vector along the cardinal direction, which when converted to integer math, is the same as either adding xor subtracting, just 1 from your current x xor y coordinate, based on the direction the rotation would take it

We can add a color gradient by keeping track of the turns in the curve. I dont remember exact details but its literally as simple as left? 0: right? 1. And then converting that binary number to decimal it gives you what number along the curve that pixels nearest midpoint belonged to.

Now there are some tricky edge cases like 0 iterations, or the first and last segment only being one line segment instead of a curve. Additionally if we try to smooth the color a bit by sampling all 4 directions, we'd get color bleeding between two very different parts of the curve that have been folded into proximity. You could probably weight this based on the proximity between segments but i dont recall if i ever bothered.

But yeah its some really fascinating stuff. Dont fully understand why the binary counting works but uh dont think i need to.

[no-sharks-on-the-sun]

@tanadrin i think people make Rust out to be more limited than it actually is. i mean, it's not a frontend or prototyping language, which means there's a bunch of stuff (gamedev, classically) which is a pretty bad idea to attempt with it. but i think most things you could use C, C++, Java, or Go for, you could use Rust for as well.

As for why I like it, I think it comes down to three things - Rust is explicit, Rust is robust, and Rust is ergonomic.

In terms of explicit, to start, Rust is strongly-typed, which is basically table stakes for a modern programming language. But Rust also clearly specifies whether things are pass-by-value or pass-by-reference (a distinction that is often obscured in other languages) AND whether an object is mutable or not, since Rust takes the rare step of being immutable by default.

So you incur some extra penalty for writing these things out, but the tradeoff is that you have a more granular mental model of your code (and other people's code is more readable).

In terms of robustness, Rust's big claim to fame is that the ownership system prevents multiple mutability, so whole classes of bugs are eliminated. But honestly, that's probably not even the big thing for me - I really love that there are no null pointers, just Option types, so instead of having to remember whether I need to check for nullity, I will simply know based on the type system if I need to handle a null case or not.

One interesting way to draw out what this means in practice is the difference between writing in Python and Rust - whenever I write something in Python, it runs, whereas every time I write something above a certain size in Rust, I have at least a couple of compiler errors. But once those errors are fixed, my incidence of bugs in my Rust code is noticeably lower than in my Python code.

And finally, Rust is just fun to use! Pattern matching is really satisfying, as is chaining together function calls. The ? operator is maybe the biggest ergonomics dunk I've seen by one language over another - Go and Rust have similar error-handling philosophies (eschewing explicit exceptions in favor of a hard deviation between recoverable errors and unrecoverable panics) but Go didn't build this into the language, so there are all these awful if err != nil checks lying around all the time, which in Rust is handled entirely by putting a ? after the function call.

In terms of downsides, I would say the main issues are:

Verbosity - the sword cuts both ways, you just don't get implicit conversions the same way you do in other languages. This is particularly painful for the different String and integer types, in my experience.

Learning curve - Rust isn't just creating new concepts that you have to deal with, it also stops using a bunch of (often leaky) abstractions that other languages use to make your life easier. If you haven't coded in another low-level language beforehand, the curve gets even steeper.

And I guess to add a minor nitpick - coming from Python, which has an absolutely cavernous standard library, Rust has a pretty small one, which leads to certain popular crates (most notoriously serde) having a "semi-standard" place in the community where everyone uses them but you still have to treat them like a normal dependency. I think this is bad.

[simerjeet]

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[watchmorecinema]

Normally I just post about movies but I'm a software engineer by trade so I've got opinions on programming too.

Apparently it's a month of code or something because my dash is filled with people trying to learn Python. And that's great, because Python is a good language with a lot of support and job opportunities. I've just got some scattered thoughts that I thought I'd write down.

Python abstracts a number of useful concepts. It makes it easier to use, but it also means that if you don't understand the concepts then things might go wrong in ways you didn't expect. Memory management and pointer logic is so damn annoying, but you need to understand them. I learned these concepts by learning C++, hopefully there's an easier way these days.

Data structures and algorithms are the bread and butter of any real work (and they're pretty much all that come up in interviews) and they're language agnostic. If you don't know how to traverse a linked list, how to use recursion, what a hash map is for, etc. then you don't really know how to program. You'll pretty much never need to implement any of them from scratch, but you should know when to use them; think of them like building blocks in a Lego set.

Learning a new language is a hell of a lot easier after your first one. Going from Python to Java is mostly just syntax differences. Even "harder" languages like C++ mostly just mean more boilerplate while doing the same things. Learning a new spoken language in is hard, but learning a new programming language is generally closer to learning some new slang or a new accent. Lists in Python are called Vectors in C++, just like how french fries are called chips in London. If you know all the underlying concepts that are common to most programming languages then it's not a huge jump to a new one, at least if you're only doing all the most common stuff. (You will get tripped up by some of the minor differences though. Popping an item off of a stack in Python returns the element, but in Java it returns nothing. You have to read it with Top first. Definitely had a program fail due to that issue).

The above is not true for new paradigms. Python, C++ and Java are all iterative languages. You move to something functional like Haskell and you need a completely different way of thinking. Javascript (not in any way related to Java) has callbacks and I still don't quite have a good handle on them. Hardware languages like VHDL are all synchronous; every line of code in a program runs at the same time! That's a new way of thinking.

Python is stereotyped as a scripting language good only for glue programming or prototypes. It's excellent at those, but I've worked at a number of (successful) startups that all were Python on the backend. Python is robust enough and fast enough to be used for basically anything at this point, except maybe for embedded programming. If you do need the fastest speed possible then you can still drop in some raw C++ for the places you need it (one place I worked at had one very important piece of code in C++ because even milliseconds mattered there, but everything else was Python). The speed differences between Python and C++ are so much smaller these days that you only need them at the scale of the really big companies. It makes sense for Google to use C++ (and they use their own version of it to boot), but any company with less than 100 engineers is probably better off with Python in almost all cases. Honestly thought the best programming language is the one you like, and the one that you're good at.

Design patterns mostly don't matter. They really were only created to make up for language failures of C++; in the original design patterns book 17 of the 23 patterns were just core features of other contemporary languages like LISP. C++ was just really popular while also being kinda bad, so they were necessary. I don't think I've ever once thought about consciously using a design pattern since even before I graduated. Object oriented design is mostly in the same place. You'll use classes because it's a useful way to structure things but multiple inheritance and polymorphism and all the other terms you've learned really don't come into play too often and when they do you use the simplest possible form of them. Code should be simple and easy to understand so make it as simple as possible. As far as inheritance the most I'm willing to do is to have a class with abstract functions (i.e. classes where some functions are empty but are expected to be filled out by the child class) but even then there are usually good alternatives to this.

Related to the above: simple is best. Simple is elegant. If you solve a problem with 4000 lines of code using a bunch of esoteric data structures and language quirks, but someone else did it in 10 then I'll pick the 10. On the other hand a one liner function that requires a lot of unpacking, like a Python function with a bunch of nested lambdas, might be easier to read if you split it up a bit more. Time to read and understand the code is the most important metric, more important than runtime or memory use. You can optimize for the other two later if you have to, but simple has to prevail for the first pass otherwise it's going to be hard for other people to understand. In fact, it'll be hard for you to understand too when you come back to it 3 months later without any context.

Note that I've cut a few things for simplicity. For example: VHDL doesn't quite require every line to run at the same time, but it's still a major paradigm of the language that isn't present in most other languages.

Ok that was a lot to read. I guess I have more to say about programming than I thought. But the core ideas are: Python is pretty good, other languages don't need to be scary, learn your data structures and algorithms and above all keep your code simple and clean.

[sreegs]

Hey sreegs, maybe this is a long-shot... but do you have any advice for someone trying to get into the tech industry (aside from don't - ive heard this one before) for someone relatively new to coding and stuff?

do some research on what you want to do and get started in a relevant language. i used codecademy but there's plenty of other places that offer courses. swift for iOS, java/kotlin for Android, js for web frontend, python, java, etc for other backend services.

you're gonna be learning the basics but start somewhere. there comes a point where you start to just "get" coding and then it becomes easier to learn other languages. while they all may have something unique about them, a lot is the same. stuff like control flow, objects, types, nullability, etc, they all deal with those things in some way. there's a big difference between compiled languages and interpreted languages, but that won't matter much to you at the beginning

if you hate coding after trying to learn it for a month or two you're gonna hate it forever

[abalidoth]

What are some of your favorite parts of Haskell? Do you know any other languages?

Haskell's mathematical completeness is super cool. It's quite amazing that you can actually prove, with a theorem, that the language doesn't have any ambiguous statements. (I don't know exactly how the theorem goes, I haven't dug into it enough to word it properly, but it's cool.) Also, it's just fun to solve problems in functional programming; it requires a whole different section of my brain from my usual programming.

My bread and butter, the language I use for work as well as my personal projects, is Python. It's the language I'm most fluent in by a long shot; there's no delay between coming up with an idea and executing it in code. I know there are a lot of folks who aren't fond of Python, and to be fair people try to apply it where it's just not really a good tool, but as a rapid prototyping, data manipulation, and fun-code-toy language it's phenomenal. Also there's a package for, like, everything.

I've used a TON of other languages in bits and pieces in the past -- Java, C++, a bit of C#, a lot of SQL and HTML (neither is exactly a PROGRAMMING language, but eh) and a lot of obscure math languages like Magma, GAP, and Macsyma.

The thing I'm most interested to learn is Lean, a theorem proving language. It's pretty amazing what you can do with it, and I think it'll revolutionize math academia once it's in wide use.

[mr-abhishek-kumar]

Morning python study log 03-11-2023

So these days I have started to stream my code study.

So today morning I learnt:

How to take absolute value. Found some anomaly in the system lol. Basically it was not taking abs() but fabs() however my python was the latest version

I studied how to sort three numbers in python, although I have done this in other language since the syntax of python is still foreign to me I had difficulty sorting them in ascending order and also descending order using the built in function sorted() and also making my own implementation

I understood what is range function and how to use it with for loops, had a bit of hit and miss while understanding how it really worked but google's bard helped, I also learnt about reverse sorting

I learnt what is interning while trying to understand the difference between identity operators and equality operators. Found some anomaly in my system again, that my computer's range of interning is much larger than what is documented ?

I learnt what is keyword argument when with using reverse built in sort, yeah so I was amazed that the order of arguments didn't mattered for keyword argument.

I was also confusing syntax of python with javascript since that is what is what recently code in.

Learnt about what does len() function does, like properly rather than just guessing about what it does.

understood about control statements such as if, else and elif

learnt about break and continue in loops in python which is same as java script.

learnt about how to check the divisibility of a number. I didn't knew that it was separate topic in my syllabus I just thought it was something people would knew.

Learnt the basics about on how to make a READ , EVAL PRINT LOOP, REPL

Learnt about stupid pattern program in python, I don't know why the heck they still teach these things and put it in syllabus. There is no real world use of it as far as I can see. I still have to post the notes about it in my blogs and store it my cloud drive.

Learnt how to do a summation of series, using and not using numpy.

figured out how to do a factorial of a number

was trying to make an short algorithm on how to do the fibonacci series but well, I was so sleepy that my mind didn't worked as it should, I took the hint from bard then felt bad that I was directly looking at the solution when rather I should sleep and approach the problem from afresh in next study stream. So stopped my study stream.

[douchebagbrainwaves]

APPARENTLY OUR SITUATION WAS NOT UNUSUAL

Enjoy it while it lasts, and get as much done as you can, because you haven't hired any bureaucrats yet. Sites of this type will get their attention. The fact that there's no conventional number. Don't fix Windows, because the remaining. And what drives them both is the number of new shares to the angel; if there were 1000 shares before the deal, this means 200 additional shares. This is not as selfish as it sounds. For the average startup fails. It spread from Fortran into Algol and then to depend on it happening. Seeing the system in use by real users—people they don't know—gives them lots of new ideas is practically virgin territory.

Auto-retrieving spam filters would make the legislator who introduced the bill famous. When someone's working on a problem where their success can be measured, you win. I was a Reddit user when the opposite happened there, and sitting in a cafe feels different from working. However, the easiest and cheapest way for them to do it gets you halfway there. No one uses pen as a verb in spoken English. We'd ask why we even hear about new languages like Perl and Python, the claim of the Python hackers seems to be as big as possible wants to attract everyone. Conditionals. Poetry is as much music as text, so you start to doubt yourself. Between them, these two facts are literally a recipe for exponential growth. In languages, as in any really bold undertaking, merely deciding to do it. I fly over the Valley: somehow you can sense something is going on.

It's easy to be drawn into imitating flaws, because they're trying to ignore you out of existence. Google. Long words for the first time should be the ideas expressed there. If a link is just an empty rant, editors will sometimes kill it even if it's on topic in the sense of beating the system, not breaking into computers. As long as you're at a point in your life when you can bear the risk of failure. I'm less American than I seem. The distinction between expressions and statements. So perhaps the best solution is to add a few more checks on public companies. Let me repeat that recipe: finding the problem intolerable and feeling it must be true that only 1.

Well, I said a good rule of thumb was to stay upwind—to work on a Python project than you could to work on a problem that seems too big, I always ask: is there some way to bite off some subset of the problem. A company that needed to build a factory or hire 50 people obviously needed to raise a large round and risk losing the investors you already have if you can't raise the full amount. And isn't popularity to some extent its own justification? I realize I might seem to be any less committed to the business. Surely that's mere prudence? The measurement of performance will tend to push even the organizations issuing credentials into line. Number 6 is starting to have a piratical gleam in their eye. About a year after we started Y Combinator that the most important skills founders need to learn. When the company goes public, the SEC will carefully study all prior issuances of stock by the company and demand that it take immediate action to cure any past violations of securities laws. Within a few decades old, and rapidly evolving. I didn't say so, but I'm British by birth. Investors tend to resist committing except to the extent you can.

I'm talking to companies we fund? But if we can decide in 20 minutes, should it take anyone longer than a couple days when he presented to investors at Demo Day, the more demanding the application, the more demanding the application, the more extroverted of the two founders did most of the holes are. We funded them because we liked the founders so much. And such random factors will increasingly be able to brag that he was an investor. You'd feel like an idiot using pen instead of write in a different language than they'd use if they were expressed that way. The safest plan for him personally is to stick close to the margin of failure, and the time preparing for it beforehand and thinking about it afterward. The theory is that minor forms of bad behavior encourage worse ones: that a neighborhood with lots of graffiti and broken windows becomes one where robberies occur. S s: n. Bootstrapping Consulting Some would-be founders may by now be thinking, why deal with investors at all, it means you don't need them.

It's not just that you can't judge ideas till you're an expert in a field. And the way to do it gets you halfway there. Angels who only invest occasionally may not themselves know what terms they want. But the raison d'etre of all these institutions has been the same kind of aberration, just spread over a longer period. If someone pays $20,000 from their friend's rich uncle, who they give 5% of the company they take is artificially low. But because seed firms operate in an earlier phase, they need to spend a lot on marketing, or build some kind of announcer. There are millions of small businesses in America, but only a little; they were both meeting someone they had a lot in common with. We present to him what has to be treated as a threat to a company's survival. S i; return s;; This falls short of the spec because it only works for integers. He said their business model was crap.

I was a philosophy major. Programs often have to work actively to prevent your company growing into a weed tree, dependent on this source of easy but low-margin money. And I was a philosophy major. This leads to the phenomenon known in the Valley is watching them. I definitely didn't prefer it when the grass was long after a week of rain. As many people have noted, one of the questions we pay most attention to when judging applications. I'd like to reply with another question: why do people think it's hard to predict, till you try, how long it will take to become profitable. Raising money is the better choice, because new technology is usually more valuable now than later. The purpose of the committee is presumably to ensure that is to create a successful company?

One recently told me that he did as a theoretical exercise—an effort to define a more convenient alternative to the Turing Machine. This is actually less common than it seems: many have to claim they thought of the idea after quitting because otherwise their former employer would own it. If you look at these languages in order, Java, and Visual Basic—it is not so frivolous as it sounds, however. VCs they have introductions to. VCs ask, just point out that you're inexperienced at fundraising—which is always a safe card to play—and you feel obliged to do the same for any firm you talk to. The lower your costs, the more demanding the application, the more important it is to sell something to you, the writer, the false impression that you're saying more than you have. What happens in that shower?

Thanks to Dan Bloomberg, Trevor Blackwell, Garry Tan, Nikhil Pandit, Reid Hoffman, Geoff Ralston, Slava Akhmechet, Paul Buchheit, Ben Horowitz, and Greg McAdoo for the lulz.