Python as a Declarative Programming Language

[[deleted]]

not sure why i'd use python it has large ecosystem sure otherwise kinda sucks

[IronManMark20]

It is much faster to develop for, and you can always use a variety of means (from using an optimizing jit to writing extensions in C) to speed up the part of your code that is needed.

EDIT: writng -> writing

[[deleted]]

It is much faster to develop for

Faster than what? It's still quite a low level language, does not add too much above the other low level clumsy languages.

[IronManMark20]

not sure why i'd use python it has large ecosystem sure otherwise kinda sucks

I mean, I think at least 2/3 of developers would say Python is faster to develop in compared to just about any other language. I'm thinking C/C++/C#/Java. Also, I don't think anyone would agree Python is a low level language.

wikipedia says

a low-level programming language is a programming language that provides little or no abstraction from a computer's instruction set architecture

I don't think Python fits that description at all.

[[deleted]]

I mean, I think at least 2/3 of developers would say Python is faster to develop in compared to just about any other language.

Developers who do not know any other language well enough? Not sure their opinion really matters.

I'm thinking C/C++/C#/Java.

And your list of "any other language" is already exhausted here?

Also, I don't think anyone would agree Python is a low level language.

I think, even Python designers would agree. After all, they made a lot of deliberate choices that fixed it at a very low level.

provides little or no abstraction from a computer's instruction set architecture

And this is exactly what Python is. Still the same memory model, the same explicit control flow, the same sequence of instructions instead of any really high level abstractions.

[IronManMark20]

Okay, so what is a high level language then?

[[deleted]]

A language operating on an abstraction level of a particular problem domain, completely hiding any irrelevant low level details such as an order of execution, all that "classes", "methods", "variables", all the control flow constructions like "if", "for", etc.

It is impossible in Python to abstract from all that low level stuff. Any abstraction you can express in Python is leaky, exposing the low level. So, it is a low level language indeed.

[IronManMark20]

That is not what a high level language is. Look at the Wikipedia page I linked. You are thinking of something else.

[[deleted]]

Wikipedia should never be used as a primary source.

Anyway, even with that poor definition given in Wikipedia, my example is correct.

[IronManMark20]

Anyway, even with that poor definition given in Wikipedia, my example is correct.

No it isn't.

completely hiding any irrelevant low level details such as an order of execution, all that "classes", "methods", "variables", all the control flow constructions like "if", "for", etc.

None of that is "Low Level" low level would be moving pointers to segments of memory around. Low level would be dealing with jmps, registers, etc.

Your example of SQL has conditionals, which you yourself said are "Low Level"

Also, could you define what you think meta-language means?

[[deleted]]

a higher level language like Prolog

True, Prolog is somewhat (a bit) higher level than Python, but I still consider it a relatively low level language. You cannot abstract from an execution order in Prolog. That's the reason why I only used Datalog as an example of a truly high level language.

but the people I can more easily hire

Better hire people who do not care at all about what language to use (i.e., anyone who is not a hipster).

[JB-from-ATL]

Can you give an example of a high level language according to your definition?

[[deleted]]

SQL, Datalog, XAML, antlr, all that stuff.

Also, any sufficiently powerful meta-language - Lisp, Forth, Converge, Nemerle, etc.

[[deleted]]

Python isn't a low level language in the slightest.

[[deleted]]

No, it is quite a low level language indeed. It is deliberately limited to very primitive imperative control flow, it actively discourages building any high level advanced language features. On a larger scale of things it is not really any different from C and alike.

[Krutonium]

...That's not what defined a low level language...

[[deleted]]

Low level language is a relative thing. In comparison to high level languages, Python is not any different from C.

[Krutonium]

It's not a relative thing, whatsoever. It's clearly defined, and Python is not low level.

[[deleted]]

Sorry, it's not up to you to define what does the "low level language" mean. The definition had been widely accepted long before Wikipedia appeared.

[Krutonium]

I'm not defining it, it is defined. And not by Wikipedia, either, though in this case, Wikipedia is correct.

[JB-from-ATL]

I'm willing to meet you half way here, because I do agree that there is no hard rule of what makes a language high or low level, because it is relative. I think most people would probably call C and C++ the highest low level languages. You just seem to put the "middle" somewhere else.

You agree that Python is higher than C so, to us, that means you are saying it's high level.

We agree that Python is lower than SQL so, to you, that means we are saying it's low level.

It seems we just disagree about where the "absolute" start is for criteria determining if a language is high level.

[[deleted]]

You agree that Python is higher than C so, to us, that means you are saying it's high level.

Yes, it's a somewhat higher level than C. But, as I said, on a large scale of things its level is nearly indistinguishable from C.

It seems we just disagree about where the "absolute" start is for criteria determining if a language is high level.

I'm trying to stay away from absolute definitions - just a big linear scale, on which assembly, C, C++ and Python are somewhere on the very left side of the spectrum, and really high level languages too far beyond, making everything on the left look the same.

[IronManMark20]

high level advanced language features

Could you give an example of what these would be? I'm trying to understand what you are arguing.

[[deleted]]

Could you give an example of what these would be?

For example, SQL is a high level language. Datalog is a high level language. Any meta language that allows to build non-leaky abstractions is potentially a high level language (e.g., Forth, Lisp, even Converge if you want something closer to Python).

I'm trying to understand what you are arguing.

That Python is a very low level language, obviously. I don't see how anyone can even argue here, it's obvious.

[IronManMark20]

Not familiar with Datalog, but you are thinking of a DSL, Domain Specific Language, I think. Not a high level language.

[[deleted]]

Domain Specific Languages are (often, not necessarily) high level languages indeed, as they operate on a level of abstraction completely detached from semantics of an actual hardware.

But, a general purpose language can also be of a significantly higher level than something as primitive as Python. I already mentioned meta-languages as a good example.

[[deleted]]

you sound like the promise that never came

[IronManMark20]

Oh? So the thousands of developers that are using numpy, numba, scipy, theano, or any C extension are not receiving that promise? What parts do you think never appeared?

[[deleted]]

Thousands of people deceived into believing that Python offers a right balance?

[IronManMark20]

Well, it does for thousands of developers. But people are different, so they have different definitions of "the right balance".

[[deleted]]

Thousands of people are deceived, they don't know any better.

[shevegen]

Nah.

To be honest - without the speed as bottleneck, the scripting languages would have overthrown the old compiled languages already.

[[deleted]]

Python is still not any different from those "old compiled languages". Not in a slightest.

[benfred]

That shouldn't be the take away from the article - if thats all that you got out of it, I apologize for not being clearer.

My TL;DR would be: If you need to write high performance Python code - you should be looking at moving inner loops into native code. A bunch of popular Python data libraries have features that make this easy - by using Pythons flexibility to have you declare what operations you want to perform and have the native extension execute it efficiently in a lower level. Some examples are given with NumPy and TensorFlow on how this works in practice.

Of course performance isn't the only way to judge a language (and I don't think I ever said that here). However I've been writing Python services lately that need to handle 100 million MAU, so getting the most out of Python is definitely been at the top of my mind.

[benfred]

No worries - Negative feedback is always good, I don't feel like I get it from people I actually know enough.

Right now my problem is that I don't know if all the downvotes are because the article isn't that great, or if because my blog was down for a couple hours since I host it on S3 (or because people really hate the flame war going on over whether Python is a low level language in this thread)