Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Ask PG: Lisp vs Python (2010)

news.ycombinator.com

Post reply on HN
Print view View original

41–50 of 200 posts

Re: Ask PG: Lisp vs Python (2010)

#41

Post by zatara »

lisper wrote: post #35
jerf wrote: post #13

The Lisp vs. Python story really hasn't changed terribly much in the past five years or so. Both are still great languages once you learn to speak the idioms of the language. Both languages have persistent problems with people refusing to do so and then bitching that it's not $SOME_OTHER_LANGUAGE. Both languages have places where I'd suggest one of them over the other. Neither language is even close to a replacement…

> The Lisp vs. Python story really hasn't changed terribly much in the past five years or so. Actually there have been three significant developments in the last five years that IMO tilt the scales back over to the Lisp side: 1. Clojure 2. Clozure Common Lisp a.k.a. CCL (a very unfortunate confluence of names -- the fact that Clojure and Clozure differ by only one letter but otherwise bear almost no resemblance to ea…

Could you elaborate a little more on CCL? I thought it was mainly used to access Cocoa frameworks, but maybe things have changed since the last time I checked it. Are there any chances it can now work with Cocoa touch?

Re: Ask PG: Lisp vs Python (2010)

#42

Post by lisper »

jerf wrote: post #37
lisper wrote: post #35

Earlier quoted context omitted.

> The Lisp vs. Python story really hasn't changed terribly much in the past five years or so. Actually there have been three significant developments in the last five years that IMO tilt the scales back over to the Lisp side: 1. Clojure 2. Clozure Common Lisp a.k.a. CCL (a very unfortunate confluence of names -- the fact that Clojure and Clozure differ by only one letter but otherwise bear almost no resemblance to ea…

Fair about Clojure, I was assuming Common Lisp. Point 3 I consider not much net change, though, as the same is true of Python, and pretty much every other competitive language.

Before, Lisp had the edge in native code compilation and functional programming, Python had the edge in libraries. In the modern landscape, that made Python win IMO. Now CL has caught up to Python (mostly -- it's 90% of the way there) in libraries and retains its edge in the other two areas, so in my book CL has pulled back into the lead. YMMV.

Re: Ask PG: Lisp vs Python (2010)

#43

Post by pg »

This question sounds like it's from 2005 rather than 2010. Lisp seems to have become fashionable again now, thanks to Clojure.

I'm sure Python has very good libraries, but I would find it constraining to program in a language without proper macros.

Re: Ask PG: Lisp vs Python (2010)

#44

Post by silentbicycle »

metageek wrote: post #39
francoisdevlin wrote: post #7

I'm a Clojure guy that just wrote my first Pylons app. Here's my impression: 1. Python doesn't suck. I was able to mix FP & OOP approaches to get to my goal fairly quickly. 2. iPython was fun to use, helped out a lot, but it's not SLIME. 3. Guido has an excellent goal with making code readable, and significant white space is not a bad choice. However, I find being able to analyze active data structures in a Clojure n…

9. INSERT MACRO RANT HERE Macros are the main reason I decided to create Adder, a Lisp-on-Python with minimal impedance mismatch. Unfortunately, the first macro-heavy program I wrote turned out to be really slow, because macros engage the compiler, which, of course, is in Python. When I first tried it, it took something like 50s at 2.4GHz, virtually all of which was the compiler. (The compiler runs at load time; obvi…

> Unfortunately, the first macro-heavy program I wrote turned out to be really slow, because macros engage the compiler, which, of course, is in Python.

The Python byte-compiler, specifically, appears to be fairly slow. I hadn't really thought much about this, but while contributing to a benchmark yesterday (http://news.ycombinator.com/item?id=1800396), it wound up staring me in the face. There's actually surprisingly little difference performance-wise in running Lua from source vs. precompiled (both pretty fast), whereas the difference between Python and pyc in my benchmark was wider than every other possible pair in the chart except python interpreted vs. "echo Hello World". (I didn't have any JVM languages, though.)

I don't really do eval-based metaprogramming in Python, but do so on occasion in Lua. I thought I felt better about doing so because Lua is syntactically much simpler (and has scoping rules that make avoiding unexpected variable capture easy), but the Lua compiler itself also appears to be substantially faster than Python's. (It doesn't do much analysis, but still usually runs faster than Python.)

And yes, it's not as good as straight-up Lisp macros, but Lua's reflection also covers a lot of low-hanging fruit that macros would otherwise handle. The biggest thing lacking in Lua compared to Lisp is an explicit compile-time phase for static metaprogramming. (Code generation is an inferior alternative.) Lisp macros win big in part because they can avoid the overhead of parsing, but parsing Lua is fairly cheap thanks to its small, LL(1) grammar (http://www.lua.org/manual/5.1/manual.html#8).

Re: Ask PG: Lisp vs Python (2010)

#45

Post by gigamonkey »

norvig wrote: post #23

Peter Norvig here. I came to Python not because I thought it was a better/acceptable/pragmatic Lisp, but because it was better pseudocode. Several students claimed that they had a hard time mapping from the pseudocode in my AI textbook to the Lisp code that Russell and I had online. So I looked for the language that was most like our pseudocode, and found that Python was the best match. Then I had to teach myself eno…

I've had a similar experience, lately while writing and editing pieces for Code Quarterly--I've written the same basic algorithms in Javascript, Python, and Common Lisp to play around with them. I find the Python the best vehicle for conveying the algorithms despite being more fluent in Common Lisp.

But I've also been astounded at how slow CPython is compared to SBCL (the Common Lisp implementation I use) when I have to do long runs to gather data. (For the things I've been playing around with, my Common Lisp implementations have been something like 5 to 20 times faster.)

Re: Ask PG: Lisp vs Python (2010)

#46

Post by edw519 »

norvig wrote: post #23

Peter Norvig here. I came to Python not because I thought it was a better/acceptable/pragmatic Lisp, but because it was better pseudocode. Several students claimed that they had a hard time mapping from the pseudocode in my AI textbook to the Lisp code that Russell and I had online. So I looked for the language that was most like our pseudocode, and found that Python was the best match. Then I had to teach myself eno…

In terms of programming-in-the-large, at Google and elsewhere, I think that language choice is not as important as all the other choices: if you have the right overall architecture, the right team of programmers, the right development process that allows for rapid development with continuous improvement, then many languages will work for you; if you don't have those things you're in trouble regardless of your language choice.

Thank you, Peter. This is how I have felt for years, but could never find words that describe it as well as you just did.

Someone should write a program that automatically posts this paragraph at the top of every language war thread. I think they should write that program in php :-)

Re: Ask PG: Lisp vs Python (2010)

#48

Post by miloshh »

ced wrote: post #4
poet wrote: post #2

An approximation of some of Norvig's recent thoughts (Feb 2010): "(1) It just turned out that when Google was started, the core programmers were C++ programmers and they were very effective. Part of it is a little bit of culture. (2) Early Lisp programmers (Erann Gat) at Google actually noticed that other programmers were equally or more productive. It has more to do with the programmer; we're getting to the point wh…

That reminds me of a cool story, in Norvig's talk about Python... When he finished Peter [Norvig] took questions and to my surprise called first on the rumpled old guy who had wandered in just before the talk began and eased himself into a chair just across the aisle from me and a few rows up. This guy had wild white hair and a scraggly white beard and looked hopelessly lost as if he had gotten separated from the tou…

That is a cool story...

Though, may I add that Python (or any other modern programming language) can manipulate its own code as data - only not as gracefully as Lisp. In other words, a Lisp program is its own AST - but in other languages the AST is only a "parse" away (and Python specifically makes computing it very easy).

Re: Ask PG: Lisp vs Python (2010)

#49

Post by francoisdevlin »

leif wrote: post #34
francoisdevlin wrote: post #7

I'm a Clojure guy that just wrote my first Pylons app. Here's my impression: 1. Python doesn't suck. I was able to mix FP & OOP approaches to get to my goal fairly quickly. 2. iPython was fun to use, helped out a lot, but it's not SLIME. 3. Guido has an excellent goal with making code readable, and significant white space is not a bad choice. However, I find being able to analyze active data structures in a Clojure n…

Re: 8, you don't need decorators to compose functions: def comp(f, g): def h(*args, **kwargs): return g(f(*args, **kwargs)) # fix up h.__doc__ and friends return h or simply (lambda the, args: g(f(the, args))(x, y) (don't remember comp's semantics, is (comp f g) = f o g or g o f?) too long; don't read: Decorators are certainly cool, but semantically they represent something more like a pattern than a FP construct. A…

To expand on what I was thinking with #8, here's how I'd implement a decorator in Clojure

(def my-decor (partial comp decor-bevior))

Done.

Re: Ask PG: Lisp vs Python (2010)

#50

Post by 8ren »

norvig wrote: post #23

Peter Norvig here. I came to Python not because I thought it was a better/acceptable/pragmatic Lisp, but because it was better pseudocode. Several students claimed that they had a hard time mapping from the pseudocode in my AI textbook to the Lisp code that Russell and I had online. So I looked for the language that was most like our pseudocode, and found that Python was the best match. Then I had to teach myself eno…

Do you also find your pseudocode (and therefore python) clearer, or was it entirely pedagogical?

Redesigning a data format to match how I notate and think about it, to minimize my cognitive load, has been very helpful to me.

The long-term trend in computers seems to be to trade performance for helping the developer.

> when the main goal is communication, not programming per se

This reminds me of debates about the scientific method. Some say that you can test hypotheses etc alone without publishing and you are doing science; but others define science as a community activity, and so without publishing, it is not 'science'. While I love the idea of the lone researcher, and clever insights definitely come from individuals, without a community there is no SOTSOG.

Post reply on HN