Ask HN: What does Ruby have that Python doesn't?

https://news.ycombinator.com/item?id=283639

by globalrev • 18 years ago

66 221 18 years ago

news.ycombinator.com

About 6 months ago I decided to learn either Python or Ruby because I wanted a language to write webapps and simple computergames fast.

I kind of tried both for a while and Python gave the better impression in every way, readability, ease of use, libraries, documentation, expressiveness etc.

But there are so many really enthusiastic posts about Ruby and while Python has a lot of users and is very popular and successful I rarely see anyone rave about it. But maybe that just means it has gotten mainstream.

But anyway I like the Python philosophy that there should preferrably be one obvious way to do things. While similar in most ways, there the languages differ.

So, what do you Rubyists like so much about Ruby? Especially what do you think Pythion lacks?

davidw3• 18 years ago

I don't think Python lacks much, if anything. It's a very fine language, with a great community. Over the years though, I just lost interest in it, and have come to prefer Ruby after having rediscovered it because of Rails. It's pretty much a matter of taste: I like the syntax and convenience more.

One (fairly minor) real world case where the syntax makes a difference is in web templates: you can use Ruby pretty much straight up to do templating, but Python requires more hoops and hacking, due in part to the whitespace issue. I like the fact that Ruby is flexible enough to be used as-is for templates as well as other code. BTW, it also needs to be said that that is the only place I've ever noticed the whitespace issue being any kind of problem: it's not the big deal that some python detractors make it out to be.

In short: if you're happy with Python...great! Keep using it, you made a good choice. If you want to learn another language, pick something a bit further from it... say, Erlang, Tcl, Java, or C, depending on what your needs are.

gaius9• 18 years ago

Note that Python is sensitive to indentation not whitespace per se. So long as your line is at the right level there's no difference between

    a=1+2

and

    a = 1      + 2

In fact I wish Python were more sensitive to whitespace, then I could say my-variable without it mistaking a hyphen for a minus.

rbanffy2• 18 years ago

"then I could say my-variable without it mistaking a hyphen for a minus"

That's something cool. It would involve a new PEP and aggressive enforcement of PEP 8

gtani3• 18 years ago

HAML: kinda looks like python, if you stand far enough back from the monitor

Python's got dozens of ORMs, templating libs, web frameworks, unit test libs. The embarassment of riches definitely an issue, you could spend a week reading about python ORMs alone.

rit4• 18 years ago

I've always taken the approach of learning both and deciding for myself. If you're interested in true proficiency and building something for yourself, go with whatever rings most true to you.

I liked Ruby, but found that Python clicked better for me. That, and call me crazy - but I prefer quiet competence to foaming at the mouth zealotry. There are plenty of people who rave about Python - but they've been doing it for a lot longer than the Ruby people (simply age of language).

Ruby also has gotten lots of people hooked via Rails, and that seems to be where most of the evangelism is coming from.

(edit: commented to clarify my meaning below, in another comment: http://news.ycombinator.com/item?id=283771)

ericb• 18 years ago

>> but I prefer quiet competence to foaming at the mouth zealotry.

Do you really pick your language by your perception of its users? I'm not sure that's a great criteria for choosing a tool. If an annoying dinner guest admired the butter knives, would you butter your roll with a fork?

iron_ball• 18 years ago

Well, working extensively with a language means working with its community, as a reader of news and documentation if nothing else. The size, expertise, and helpfulness of the community are all important factors in deciding whether to adopt a language. If a programmer finds the community annoying, that could be a legitimate problem.

rit4• 18 years ago

No sorry, my first comment was pre caffeine and didn't quite explain things as well as I would have liked.

I was reflecting on the original poster's comment:

"But there are so many really enthusiastic posts about Ruby and while Python has a lot of users and is very popular and successful I rarely see anyone rave about it."

It was a poor choice of words on my part - I meant to characterize that evangelism doesn't necessarily mean it's a better tool. I was reflecting more on his commentary about "enthusiastic posts" in my comment than any personal opinion on Ruby ( I find a bit of zealotry in the Rails people but that's neither a bad thing nor is it my place to comment on it). My preferences tend these days towards being slightly turned off by the loudly evangelised toolsets, simply from past experience of what happens to the communities when they get like that. After things calm down, and the happy masses move on to the Next Big Thing(tm), the languages, tools etc are often quietly solidified and iteratively improved (uncelebrated, in many cases) by those that stick around.

I recently came back to Perl, having joined a firm building systems in Perl, and was surprised at how much has happened in Perl in the 4 years since I stopped working with it. While so many of those that formerly evangelised about Perl moved on to Ruby and Python, the people who were forced to continue working with it every have found ways to improve it. Adding a try/catch syntax with proper exceptions, and similar constructs (albeit a bit Monkey Patch-ey) have made it much easier to work with.

It will be intresting to see what happens to Ruby when the Next Big Thing happens, and the community sheds a lot of it's more fickle members. That's not to say Ruby isn't a fantastic tool now, but I'm interested to see the maturity that comes from the difference between those who think it's really the best tool for them as opposed to the tool that everyone loves.

scott_s2• 18 years ago

I think a better analogy is choosing a house to live in and its neighbors.

Alcides• 18 years ago

Rails. but you have Django which is better ;)

Seriously, I envy ruby's blocks and being able to redefine a class later in your code (monkeypatching-easy-syntax).

Oh, and Shoes :)

pavelludiq• 18 years ago

Yeah, me too. Is it a good idea to learn ruby just to use shoes? I mean is it easier that qt/tk/gtk+/wx?

utnick• 18 years ago

you should try it out and see if you like it.. shoes is a good way to learn ruby

shoes is good for simple apps. But if you need complex controls like trees and sliders, coding in shoes would get annoying. Also the documentation for shoes leaves something to be desired.

but it is pretty fun.. i'm coding a shoes app right now and would recommend it

ghiotion• 18 years ago

I chose RoR over Python/Django for one simple reason: RoR's tight integration with the Prototype AJAX javascript library. Personally, I like Python as a language much better than Ruby. But if I'm going to code up a Web app, I want easy AJAX integration - I don't want to hand craft a bunch of javascript. It's not that I've got anything against writing javascript, but I hate, hate, hate trying to debug it.

cstejerean4• 18 years ago

Tight integration with prototype is one of the things I don't like about Rails, mainly because I don't like Prototype (I'm a big fan of JQuery).

aconbere18• 18 years ago

I have to agree with the other commenter. I prefer to "roll my own" here. Not because I don't like it when frameworks take care of mess for me, but because I'm constantly frustrated by how frameworks handle JS. A quick and dirty RESTful JSON api is easy enough to build in either framework, and once you're there, Ajax becomes pretty trivial (especially with any of the nice JS Frameworks)

jonhohle2• 18 years ago

this is never really brought up, but objects in ruby fully encapsulate their instance and class variables. the only way to get at them from the outside is by sending an object a message asking for them (like Smalltalk or Objective-C). what appears to be setting a property on an object, is really calling a method: `foo.bar = 5` isn't directly setting the property, its calling a method named `#bar=`

in my opinion, this is powerful and elegant.

that being said, i have little experience with python, but what i've seen never wowed me. it seems like it has a well written collection of libraries, but that seems to come from the community more than the language. correct me if i'm wrong.

cpr• 18 years ago

You can do exactly the same thing using Python descriptors. No advantage to Ruby here.

jonhohle2• 18 years ago

but its not enforced by the language or the object model. advantage ruby ;)

simonw• 18 years ago

Two good things and one bad thing. The good things are multi-line lambdas (which Ruby calls blocks) and loose syntax rules, which I found weird at first but is the secret behind all of that DSL stuff.

The bad thing is the cultural tendency of the Ruby community towards monkey patching, which in my opinion trades long term maintainability for short term convenience.

LogicHoleFlaw7• 18 years ago

With the rapid growth of the community I think that the monkey patching mentality will eventually subside. More and more toes are being stepped on.

aconbere18• 18 years ago

To be fair... blocks are not lambda's, but things would be a lot better if they were.

gaius9• 18 years ago

My experience is that the languages are similar in terms of features, but the communities are very different and there isn't much overlap between them. Ruby types tend to be younger, focussed on the web, probably employed as full-time developers. Python types tend to be older and not employed as developers, but write code as part of their main jobs. Python people often have experienced a nightmare of unmaintainable Perl, that is why there is the insistence on there being one right way to do everything (which is the exact opposite of what Perl people believe). Ruby people (being younger and hence less experienced) haven't, which is why they talk about expressiveness and do things like monkey-patching. Neither group is "smarter" and neither language is "better". The choice is a choice of what community you want to join, not a technical one.

cstejerean4• 18 years ago

"Python types tend to be older and not employed as developers, but write code as part of their main jobs."

I'm curious, how did you arrive at that conclusion?

gaius9• 18 years ago

Mainly through direct observation. Among my own circle of friends, it's surprising how neatly we (well, those of us who use either language) divide into those categories. But you can see the pattern in job ads, discussions on mailing lists and in the domain-specific libraries for each language too. As many people got into Python through NumPy as a MATLAB alternative as got into Ruby via Rails, I'll bet.

Like I say, this isn't a good thing or a bad thing, it's just interesting.

OneSeventeen• 18 years ago

I agree that this is the big decision point. I'm a Ruby guy and I've looked at Python several times and it never really stuck (I could work on a project that use Python, it just wouldn't be as fun as a project using Ruby to me). I could complain about various technical details, but if I'm entirely honest it would just be minute, meaningless, bitchy detail nitpicks.

DocSavage3• 18 years ago

From my observation, the ruby community is heavily skewed by the recent influx of Rails programmers, which is web dev and younger. Old-school ruby folks (the guys who were ruby gurus when Rails was still an infant) have different characteristics: older, less confrontational, veteran programmers, Matz-like. A generalization for sure but my impression.

The python community has done significant development in science/math so they have stronger libraries in those fields. Python has had an influx of Railsy people due to Django and might get a shot in the arm from Google App Engine.

From a language perspective, I like the wealth of libraries for python. I like that many reference/experimental applications on web stuff is in python. The whitespace issue for me has disappeared and I'm actually leaning toward liking it more than ruby's block delimiters. The template/erb issue can be diffused by looking at HAML. (That's a cool way of incorporating pythonic indentation to templates.) Unicode is solid in python.

Ruby is a better choice if you like to reshape the language into something that could potentially look un-Ruby. It's possible I haven't gotten far enough into python yet, but I can see why metaprogramming and DSLs are more prevalent in ruby than python, and it's not just "one way" culture. (Ruby's optional parentheses for method calls is an example of a language feature that fosters DSL use.)

aristus2• 18 years ago

I have to agree. Ruby has incredible flexibility, but how it's been used by "the kids" in things like Rails (and especially Rails extensions) makes my skin crawl.

This also bugs me to no end: nil.to_i == 0, 0 evals true, but nil evals false.

Python's lack for me is anonymous functions. It's cumbersome to set up 40 slightly different named functions and a hash table (or some "factory pattern" thing) to do the same job as 3-4 lines of Ruby. Symbols are nice too.

But for my personal work I choose Python for the libraries, cleanliness, and performance.

olefoo• 18 years ago

Another factor that pushes python forward among people for whom programming is a means not an end is that it is a primary scripting language for Ubuntu and is heavily used in the Red hat descended distros as well...

On some level choice of programming language is irrelevant, since any specified functionality can be written in any turing complete language. Arguments about programming language are arguments about style rather than substance.

I suspect that the python vs. ruby debate is like arguing about whether keyboards or guitar are superior musical instruments. They both have their place and the world would be sadder and smaller place if either one went missing.

maxklein8• 18 years ago

The languages are similar enough that it does not really matter. Just pick any, but make sure you balance it out by also knowing a low level language or a functional language.

Remember this: Every language you learn is a big investment in time and energy, and I don't think many people can be really proficient in more than 2 or 3 languages. Some can, but not most.

So, choose wisely, because you will likely be using that language for a long time to come. I personally prefer python because it's more widespread and right now, you have more available to you when you know it than with ruby.

subwindow4• 18 years ago

I couldn't disagree more.

Even if you spend a month learning Ruby and never use it again, it will still irrevocably change the way you approach writing code.

maxklein8• 18 years ago

You mean that ruby has a greater learning effect than python on a C++ programmer?

aconbere18• 18 years ago

I definitely did not have this effect on me. Usually when I hear comments like this it's from Java programmers. But coming from a background of already knowing several expressive dynamic languages (Python, Perl) and having a strong functional background in Lisp. I didn't really find Ruby that mind blowing.

Very cool? YES! worth learning? Absolutely! "changing the way I write code irrevocably? Not a chance!

tptacek15• 18 years ago

I'll join the peanut gallery and suggest that if "irrevocably changing the way you approach writing code" is the goal, you spend a month with Lisp or C before you do Ruby.

tokipin9• 18 years ago

maybe i'm an incredible genius or something, but give me a week or two and i'm writing code at an advanced level in any language. it's pretty easy. it more or less involves making an actual project in that language, which cold turky sink or swimly requires that you know the language at least decently

i think it's mostly mentality. if you think languages are hard to learn, then they will probably seem that way because you will allow yourself too much time to play around with mere details, whereas if you recognize there isn't much to them, you can accomplish a lot in no time at all

icey3• 18 years ago

Obviously you've never met Haskell.

And if you hit the reply button and say that you have, then I demand to see code samples.

maxklein8• 18 years ago

I think it is more likely that you do not recognize your own flaws. It takes a real genius to be able to learn the little things about C++ in a week or two.

A language is not just the syntax of the language itself, it's also the code style, the convention, the best practise, the language specific stuff, the API of the libraries available, the best way of doing things with libraries.

If you use python to write simple number crunching console applications, then switch to ruby, that is an easy switch.

But if you're writing a Web application using Python and Django and you switch to writing DirectSound using C++, and you tell me you can do this in a week, then you are a genius.

The syntax of languages are trivial, but that's like saying you can discover the colors used in a painting. That's the easy part. The difficult part is knowing how it works. Let me list a few examples of technologies that I think differ strongly from each other that make it difficult to switch

- MFC with C++

- Django with Python

- DirectShow with C++

- VHDL

- ASM

- Javascript with JQuery

- CSS with HTML

- Helix Framework with C++

- Quicktime API with C++

- OpenGL with .NET

- LISP

Have you ever had to switch between things on that level? Or are you talking more of a python to ruby switch?

raganwald6• 18 years ago

"Give me a week or two and i'm writing code at an advanced level in any language."

Whereas the Peter Norvigs of the world need ten years.

Sigh.

cosmo72• 18 years ago

> maybe i'm an incredible genius or something, [...] which cold turky sink or swimly requires that you know the language at least decently

If you're such a language whiz you might want to master basic English.

olavk• 18 years ago

I prefer Python, but I am somewhat envious of Ruby blocks. Also I like the idea that method calls are messages.

pdubroy3• 18 years ago

I've done quite a bit of Smalltalk programming, and I agree about the blocks. But what do you mean by "method calls are messages"?

LogicHoleFlaw7• 18 years ago

In Ruby calling a method on an object basically sends a message to the object with the name of the method and the arguments. You can hook into the dispatch code and do pretty much whatever you want with that message at the class level. I don't know the internals of Python's method dispatch that well, so I can't say how it compares in that regard.

pdubroy3• 18 years ago

Hype? ;-)

subwindow4• 18 years ago

It isn't so much about language features, as both languages are roughly equivalent in that sense.

It is about how the language makes you feel. If you're going to be spending >5 hours a day writing in some language, it is of great importance how that language makes you feel when you write it. Simply said, writing Ruby makes me happier than I've ever been while writing code.

Python is to German as Ruby is to French. You can get roughly the same message across equally well in both languages, but French just sounds so much better.

LogicHoleFlaw7• 18 years ago

Well... unless you want to sound really angry! Then er... Python is better?

I think I'm stretching the metaphor past its breaking point.

donw• 18 years ago

Two words: "French Engineering".

gdee• 18 years ago

Two counter words: Ariane, Nuclear (as in 80%+ national electricity)... not too shabby as far as engineering goes... I would add Airbus, LHC, etc... but two are enough.

comatose_kid• 18 years ago

Have you ever worked with engineers from Les Grandes écoles? You might reconsider your view.

demallien4• 18 years ago

yeah, as an engineer working in France, I can honestly say that their engineers are pretty good. The problem is that there's another grand école that specialises in producing bureaucrats (seriously!). And for whatever perverse accident of history, they are considered to be la crème de la France, so they call the shots in most large businesses. They consider themselves to be better than lowly engineers, so don't deign to listen to any suggestions about what is technically possible or not.

/bitter

:-)

cosmo72• 18 years ago

> Two words: "French Engineering".

Mmm hmm. How's that American SST coming on? I'm English and your comment even annoyed me.

timr• 18 years ago

Indeed. Whenever I'm waiting for Ruby to finish something that Python would have done faster, I like to imagine that it's taking a long lunch in a Parisian cafe, smoking clove cigarettes and picking up women.

nostrademons8• 18 years ago

I'll agree that it's about how it makes you feel, but Ruby (+ Rails) just made me feel sloppy, while Python (+ Pylons or Django) felt crisp & productive.

Really, I'd say to try both languages and pick whichever one you like best. They're very similar in what they let you accomplish, but have very different feel. What works for one person won't necessarily work for another.

eru5• 18 years ago

German can be very precise.

tokipin9• 18 years ago

personally i don't like the 'one way' mantra that Python is designed by, because it seems to imply a couple things. 1, the language is probably not as flexible and powerful as it could be. and 2, the design goal is similar in nature to that of production languages, eg Java which forces object orientation. the intentions are good... to allow the construction of readable, maintainable software by normal humans, and Python is at least not as retarded about it as Java, but i have found that languages which constrict aren't for me

so to me Python seems more of a team production dynamic language than one where i can get into flow and crank shit out

nostrademons8• 18 years ago

The practical benefit of "one true way" is that it eliminates decision points. Most of the time in a software project is wasted in making decisions; if you eliminate all decisions that are not relevant to getting the software finished, you have a huge head start on everyone else.

There's a joke going around that a Python team will finish a project before a C++ team can decide which brace style to use...

demallien4• 18 years ago

There really isn't a huge difference between the two. For what it's worth, I personally prefer Ruby because it has better support on the Mac - Apple use ruby a fair bit themselves. For example, the command line tool gen_bridge_metadata (supplied by Appleto make it possible to access system frameworks written in C from scripting languages) is itself a ruby script. I notice that on Linux it's the reverse - python seems to be the preferred scripting language.

But don't take my comments as saying only ruby is supported on the Mac, or only python on Linux - in reality it's only a light preference one way or the other.

tpherndon2• 18 years ago

The CalDAV server authored by Apple and included with OS X Server is written in Python. PyObjC receives a lot of attention from Apple employees. I don't think there's much preference exhibited by Apple one way or the other.

And vice versa, there must be some Linux distros that have tools written in Ruby, right? Particularly some of the newer ones, I seem to recall hearing that their system tools were Ruby.

evgen• 18 years ago

FWIW, the wiki that Apple includes in Leopard Server is also written in Python. Apple apears to be making much more use of Python than it is of Ruby.

BrandonM• 18 years ago

All of Gentoo's tools are written in python, bash, or C.

demallien4• 18 years ago

As I said, it's just a slight preference. But I look at things like the official Apple support for MacRuby (Apple is employing Laurent to re-implement ruby in Objective C, so that ruby objects are Objective C objects - you'll be able to program Cocoa in Ruby without having to take the performance hit of crossing a scripting bridge all of the time!), and I don't see a commensurate support of the Python world. But as I said, it's only a slight preference - Apple s evidently right behind both languages, as they make leveraging the power of OS X so simple.

thisisnotmyname• 18 years ago

The lack of built-in regular expressions is a pain point for me.

jrsims2• 18 years ago

I really like Python, but it doesn't have an equivalent to CPAN or RubyGems.

I'm actually quite puzzled by this.

shabda• 18 years ago

pypi? www.python.org/pypi

tpherndon2• 18 years ago

Read up on setuptools and the Python Package Index, aka the Cheeseshop. Setuptools hasn't yet been adopted as the one true packaging format by all library creators, but it gaining acceptance.

jrsims2• 18 years ago

Ok, awesome. And that's the same story as RubyGems. I've noticed that Python peeps are pretty big on "show me the code" anyway, but I think a lot of untapped potential is lost by not having a dead-simple distribution mechanism, as good as Python libs tend to be overall.

That's one thing I do like about Ruby; it wasn't always this way, but RubyForge + GitHub (Oh, GitHub!) + RubyGems combine to make for a very fluid feedback mechanism and make good use of The Cloud.

The result is that new libs get announced, distributed, tested, and improved by rabid Rubyists rather... rapidly.

raganwald6• 18 years ago

They're both impressive, modern languages. What I find interesting when comparing Python to Ruby is how much Python isn't like Lisp. Matz has said outright that he considers Ruby to be "MatzLisp" and it shows, whereas Guido has absolutely no problem chucking Lispy things overboard--like multi-line anonymous functions--if they do not fit the rest of the language.

Instead, Python finds another way, like powerful list comprehensions that can be used wherever Ruby would use blocks and maps.

So I would say you can learn some very interesting things from either language, and there's a good chance they will be different interesting things.

aconbere18• 18 years ago

Matz might say that, but doing functional things in Ruby is a pain in the arse as well. Blocks, Lambdas, Procs, and Methods, all which are slightly different and require transformative functions to move one into the other. That's about as far from an s-expression as you can get.

That being said, having the easy ability to create lambdas or blocks is hugely benefitial. sighs and I wish python would hop on board there, but I don't think it ever will.

raganwald6• 18 years ago

I dig: http://weblog.raganwald.com/2008/06/what-does-do-when-used-a...

eru5• 18 years ago

For functional programming what Python really misses is not a decent lambda. You can get by without.

But properly optimized tail recursion.

nostrademons8• 18 years ago

You don't really need full tail-call optimization as long as your map/filter/reduce is optimized. Nearly everything can be expressed as combinations of those.

Actually, if you have generalized folds (folds over all data types, not just lists), all recursion can be expressed in terms of a fold. That's the point of a fold function: it captures the recursion pattern over a data type, letting you parameterize just the specific operation that replaces the constructor.

In practice, I found that the mutability of basic structures was more of a problem. By default, your subscripting/attribute assignment all mutate the original object instead of creating new ones. When I did FP in Python, I did a few decorators to hide this, but it still felt like an ugly kludge that was fighting the language.

gtani3• 18 years ago

Well, they're both foundational languages, pretty much, not in the sense of this blog, i.e. most instructional language

http://mvanier.livejournal.com/998.html

but in the sense of can you put up a significant web app in 2 or 3 days, do lots of companies use it (along with C, java, C#, javascript).

r vs. p can't be reduced to 15 bullet points, but one of the best things i remember is Alex Martelli in 2003, so he was talking about ruby 1.6 and python 2.3, i believe, but still valid

http://groups.google.com/group/comp.lang.python/msg/28422d70...

and here's the last thread from May.

http://news.ycombinator.com/item?id=157269

There's the other killer apps: Python: twisted, zope, SQLalchemy, mercurial. Ruby: rake, capistrano, rspec, adhearsion, merb, puppet, metasploit. I'm sure python has a bunch more, but i've been living in rails-land.

Zak• 18 years ago

First class symbols are the big one, I think. Of course, we all know about Python's brain-damaged function literals.

eznet• 18 years ago

I think that a lot of the popularity of Ruby came not so much from Ruby itself, but Rails. I think that with the emerging popularity of Django, you are likely to begin noticing a similar influx of Python enthusiasm...

rit4• 18 years ago

Admittedly, Django was what first got me really going with Python (we started using it for some small projects as a possible replacement for PHP a few jobs ago).

There are however also some great alternatives within the Python community, in addition to Django which I no longer tend to use.

Pylons, which is very Rails like including having similar WebHelpers functions, and a port of the Rails "routes" system.

TurboGears, which is currently re-tooling itself to be based on Pylons.

And a variety of others that I'm probably forgetting.

I'm admittedly ignorant on alternatives on the Ruby side, but would be interested to see what other web frameworks people have built and the pros cons vs. Rails.

jon_dahl• 18 years ago

I'm admittedly ignorant on alternatives on the Ruby side, but would be interested to see what other web frameworks people have built and the pros cons vs. Rails.

Merb is the big one. Think Rails, but more lightweight, greater emphasis on scaling and performance, and open to several ORMs (not just ActiveRecord), templating languages (not just ERB), and Javascript libraries.

Camping is a Ruby micro-framework that's been around for a while. The framework itself is 4kb, and Camping apps are designed to sit in one file. Used a bit on the side, but not especially widely for production work.

Sinatra is a newer microframework that looks similar to web.py, but in Ruby. Looks useful, and I've been meaning to get around to it.

The nice thing about Rails, Merb, and Camping is that if you know one, the others will be familiar. They're all MVC frameworks that support ActiveRecord (and other ORMs, sometimes). They all favor convention over configuration.

kaens2• 18 years ago

And a variety of others that I'm probably forgetting.

I personally find CherryPy to be great for writing small web-apps. I haven't used it for anything larger yet, but I suspect that I'll continue to prefer it over other python web frameworks.

iamnirav• 18 years ago

I like how this conversation has gone on for so long, but on the whole, everyone's still polite and detailed in their responses. :-) warm fuzzy feeling

waldrews• 18 years ago

Though I'm pro-Python on maintainability grounds, there's one Lispish feature Ruby has that I wish were available in Python, that's not even in the Py3000 spec: continuations. The Ruby community doesn't seem to be too enthusiastic about using them though. We're just beginning to see continuation-based web framework experiments on Ruby, in the spirit of Seaside in Smalltalk.

The continuation-based web frameworks make state management on the server transparent; but they have a scalability problem since state can't move between servers or even be taken out of memory on the same server.

Now once somebody makes serializable continuations practical - certainly a hard problem - it would be a jolt to web development on at least the same that Rails has been.

LogicHoleFlaw7• 18 years ago

In Lua, the Pluto serialization library has no problem persisting coroutines, which are isomorphic to one-shot continuations. Lua isn't terribly active in the web space, though this feature has been used to good effect in games.

blasdel• 18 years ago

Serializable continuations are already practical in Smalltalk: http://www.seaside.st

tptacek15• 18 years ago

What the hell, they're only karma points:

I lived with Python for 4 years before I lost an argument at my own company and had my project moved to Ruby. I've since moved in with Ruby and haven't looked back.

* Everything in Python feels like a symbol table hack. Private methods? We have those! Just exploit this bug in the class symbol table lookup code!

* First-class symbols. There may be little difference under the hood between a Ruby interned string and a Python string atom, but there's definitely a difference syntactically. This is a difference that is hard to articulate, but if you've written much C, it's like having every "enum" you could ever want predefined for you, and completely eliminates "magic numbers".

* Blocks and lambdas. I've read GvR's take on this. I know he thinks a named function is just as good --- maybe even better! --- than an anonymous function. I had nested named functions/functors in C++ and Java. Even Tcl "uplevel" is better than Python's castrated lambda.

* Method definitions in Ruby don't need to accept a "self" argument. Again: all of Python feels like a symbol table hack to me.

* Ruby has first-class Regexps. Python has an "re" library. You know what else has an "re" library? C.

* I haven't found an expression that is better written as a list comprehension than as a map/reduce/select expression.

There are painful things about Ruby:

* The FFI is immature. Outside of Common Lisp, Python ctypes may be the best FFI out there.

* I never got Python to crash on me (at least, not where it was Python's fault). I crash Ruby once a week.

* Ruby is palpably slower than everything. If performance matters to you and you don't know C, you may be better off in Python.

* The community is led by the nose by Rails developers, which can at times feel like a worst-of-all-worlds grab bag of methodology programmers, web designers, and dabblers.

tomjen• 18 years ago

You can add inline c to ruby for the few places where speed matters.

tptacek15• 18 years ago

Yes, and that simply costs you the ability to distribute your software to anything but your own servers.

ajross2• 18 years ago

Blocks and lambdas

Yeah, but this is an area where both languages are just a mess. If python's lambda is castrated, ruby's notion of an anonymous function is tumorous. We've got blocks, procs, lambdas and methods? What's the difference?

Ruby mixes up the syntactic requirements of "passing" some code to a loop to iterate with with the data requirements of binding a function to a scope. It's just a huge mess.

LISP and Scheme figured all this out decades ago, and yet only Javascript (and, almost, perl) among common scripting languages has managed to absorb the lesson.

tptacek15• 18 years ago

You say "both languages are just a mess" as if to equate the two. But there's no comparison.

Your Ruby problem with blocks and Proc objects is a nit about elegance and semantics. How often does the difference between an actual Proc object and a block actually affect you? More importantly, if the cost of fixing that nit is that we wind up with Lisp's or Javascript's lambda notation, who would accept that? Javascript has relatively consistent semantics for anonymous functions, but extremely clumsy syntax.

Python simply doesn't have real lambdas. It has the ability to pass something called a lambda in place of a function, and that something forces you to think about things like the difference between a statement and an expression. It then tells you that you don't in fact want anonymous functions, but instead you want to define tens of itty bitty named functions and use them instead. You also "want" that "self" argument to all your methods, and you "want" to tack two underscores to the front of your method names to make them private.

So, I half agree with you. Yes, it would be nice if there was a (zero-cost) way of fixing Ruby's block semantics. Yes, I can rely on Lisp's lambda semantics slightly more than I can on Ruby's, which does start to matter when you start writing domain-specific language code. But I don't agree that this has any bearing on the Python vs. Ruby argument. Python lambdas suck.

Maascamp• 18 years ago

Interestingly enough the language everyone loves to hate, PHP, as of 5.3 has figured this out as well.

LogicHoleFlaw7• 18 years ago

Lua gets it right too.

rincewind2• 18 years ago

The "self" argument is great. It is the reason why methods in Python are normal functions and not special "methods".

It also makes this pointless but interesting piece of code possible:

  class foo(object):
     def subclassme(self):
          class subclass(type(self)):
              def __init__(self2):
                  self2.parentobj=self
          return subclass()

davidw3• 18 years ago

> Even Tcl "uplevel" is better than Python's castrated lambda.

Tcl, in its own way, is more powerful than both Ruby and Python in that only the syntax is a given. There is nothing special about 'if', 'while', and other control structures, which are not syntax, but commands. Indeed, you can write your own control structure commands in Tcl itself, with 'do ... while' being a classic example.

tptacek15• 18 years ago

You can do the same thing in Japanese Tcl using blocks.

j2d2• 18 years ago

Ruby's lambda is worse than Python's.

Can you elaborate on why you think Python's lambda is castrated?

kashif3• 18 years ago

Why is 'symbol table hack' a 'bad' word? There is absolutely nothing wrong with the way symbol tables are used in python.

earthboundkid• 18 years ago

More to the point, it's a feature, not a bug. That everything is a symbol table hack makes metaprogramming much simpler.

aconbere18• 18 years ago

I've somehow forgotten to rant about ruby's totally hackish broken tools for importing code. require and include are just heinous crimes against nice programming. (I /love/ it when I clobber my global namespace with an include in ruby).

tptacek15• 18 years ago

That's never caused a problem for me. It's also a tradeoff: in Python, you have to meticulously "import" every symbol you might need, which is tedious. I compared a really good piece of Python code (CORE's Impacket library) to a similar piece of Ruby code (Jamis Buck's net/ssh), and it's 3-1 in average number of important statements per file.

gttg• 18 years ago

* Everything in Python feels like a symbol table hack.

>It isn't bad at all. (And does not really matter)

* First-class symbols.

>Ok, but python has first class functions.

* Blocks and lambdas. I've read GvR's take on this.

>GvR is right.

* Method definitions in Ruby don't need to accept a "self" argument.

>It isn't bad at all. (And does not really matter)

* Ruby has first-class Regexps. Python has an "re" library. You know what else has an "re" library? C.

> Ruby has private methods. JAva has private methods too. Therefore ruby is bad.

And so on...

p.s. And if you need oop features why use ruby instead of java?

noamsml• 18 years ago

"p.s. And if you need oop features why use ruby instead of java?"

Probably because he values his sanity.

bootload• 18 years ago

"... I lived with Python for 4 years before I lost an argument at my own company and had my project moved to Ruby. I've since moved in with Ruby and haven't looked back. ..."

Where would we be without language wars?

Having said that the one thing that Ruby does have is current developer mindset. Important for language development and progression. Is Python to Ruby what Perl is to Php? Used a lot but not mentioned as much?

gtani3• 18 years ago

the thread's going viral, slowly

http://www.reddit.com/r/programming/comments/6xkti/what_does...

alexstaubo• 18 years ago

> Ruby is palpably slower than everything.

Try 1.9. It's usable today, and should be fully stable by January. Performance-wise, it's on par with Python.

marcher• 18 years ago

I think you might be confused as to what Python's lambdas are for. The name is very misleading - it really should be called a function expression. It's just a shortcut for declaring a function with an expression. It's useful for situations where you need to pass in a very simple utility function, as is usually the case with list.sort() and its comparison function argument.

I'm not sure what points you're trying to make with your other complaints, but I guess if you "feel" things are hackish, that's OK. What you might consider feeble-minded hacks Python coders consider simple, straightforward implementations.

cben• 18 years ago

I want to focus on one point that I find an interesting study in language design:

> * I haven't found an expression that is better written as a list comprehension than as a map/reduce/select expression.

map/select are better iff you have a concise block syntax.

For mapping with a single ready function, all styles are reasonable:

    items.map foo
    items.map { |x| foo(x) }
    map(foo, items)
    [foo(i) for i in items]

Now suppose you want to modify the mapping function to foo(bar(i)). You could cascade it:

    items.map(foo).map(bar)
    map(foo, map(bar, items))

but this quickly gets out of hand and makes modifications painful. What you really want is a place to write arbitrary expressions instead of just a function name.

With comprehensions OR a good block syntax, it's a smooth transition:

    [foo(bar(i)) for i in items)]
    items.map { |i| foo(bar(i)) }

But without one, the change is ugly and annoying:

    map(lambda i: foo(bar(i)), items)

So why wouldn't Python just embrace a nice block syntax? Precisely because this naturally leads to expressing most control structures as functions taking blocks!

Now that is not wrong in itself, but it is a question of taste. Pythonic taste favors a different approach: instead of passing the block directly to a function, have a few built-in control structures that can act as combinators.

E.g. don't write an "each" method that accepts a block - write an iterator, and use the built-in "for" loop as a bridge between the iterator and the block. Why would this be any better?

1. Because we can: it turns out that the vast majority of custom control structures can be sorted into a few patterns (iteration, pre/post guards, function wrapping), each served by one natural combinator ("for", "with", decorators). There is a price: it takes time until new patterns are recognized and the missing combinator is added (e.g. "with" is a very recent addition).

2. Decoupling: an iterator is a self-contained passive object that can be used outside of a for loop. An "each" method takes control and is less versatile.

3. Readability: seeing the combinator gives you an immediate idea about the style of flow control. This is just a matter of taste (Lisp and Ruby solve this with naming conventions).

4. Syntax taste: stupid as it sounds, passing blocks to functions is just alien to Python's syntax. Many smart people tried to marry them - and it wasn't a pretty sight...

But in the end you can't judge decisions of taste by pro/con arguments. You have to look at the sweet spots (and the sour spots) that arise in practice. A particularly nice sweet spot that arose in Python is the combination of reduction functions with generator expressions:

    sum(i**2 for i in range(10))
    any(p % i == 0 for i in range(2, p - 1))
    dict((v, k) for (k, v) in dict_to_invert)

This is very cool because the map-reduce pattern covers lots of useful computations. Of course it's just a one case and YMMV. I'm sure Ruby has its own sweet spots...

iamelgringo• 18 years ago

About 6 months ago I decided to learn either Python or Ruby because I wanted a language to write webapps and simple computergames fast.

If you're after writing simple computer games fast, then you might have a look at Pygame: http://www.pygame.org/news.html

There are also a number of visual effects companies (ILM, Dreamworks) that use Python as their system scripting language. I don't know if it's because of that community, but I find a number of graphics/games libraries in Python: http://www.vrplumber.com/py3d.py and http://vpython.org/

Blender the open source 3D modeling program used Python as it's scripting language last I checked: http://www.blender.org/

I don't know if Ruby has libraries like that or not. I've only used Ruby to mess around with Rails.

pauljonas• 18 years ago

For me, the question isn't so much what Ruby has that Python lacks, but the extra Python bits I find annoying and/or tedious:

* having to declare "self" in every method argument — reading code, it just clutters up the screen/page

* the big use of of double underscores for special methods (i.e., __init__, __str__, __getattr__, etc...) — IMV, it's gooberish...

* no switch/case statement

In defense of Python over Ruby:

* I prefer the whitespace over the Pascal-ish begin/end, especially for real life code solutions

* the Ruby shorthand syntax IMV at times obfuscates code clarity - is it a method or variable I am looking at?

That said, I'd much rather code in either Ruby or Python than in Java or C...

abdelazer• 18 years ago

After leaving Ruby (non-Rails) for Python this year, I've mostly noticed the difference in the obsession about testing. The Ruby crew is very into TDD (and now BDD)–that isn't to say that Python folks don't test (or do TDD/BDD), but simply that the tools available in Python aren't quite as polished. Ruby's RSpec, RCov, Flog, Autotest, & Heckle are all quite wonderful. I do like Nose, but get annoyed by lack of friendly code coverage tools in Python.

DougBTX2• 18 years ago

_why

mroman• 18 years ago

I would love to read pg's thoughts on this question.

Actually, I would love to read more of pg's thoughts on Ruby, what I have read of his thoughts on it has been brief yet highly positive.

petercooper• 18 years ago

Consistency in class definitions (that is, not two "types" of class). Python's packaging is less consistent. Oh, and far better community sites.

Ask HN: What does Ruby have that Python doesn't?

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