Develop Reference

Web Frameworks & Available Libraries: Is it a brave move to opt for Node.js instead of Python?

I have quite sometime now (a month or two) before I can actually start learning a web programming language; so I am still worrying about what language to learn.
Whatever programming language I choose, I'd also have to learn JavaScript alongside that language as it's the go to for client-side scripting.
I am looking at: (1) Python, Ruby, JavaScript (Node.js -- server-side & jQuery -- client-side); (2) DBMS - PostgreSQL (3) I am going to learn C/C++ anyway (but after I learn a high-level programming language among those mentioned above).
So, the question is, is it a brave move to choose Node.js/JavaScript for server-side programming? (brave in the sense, learning Python would be a lot easier and good, and you're only trying to be brave/foolish by choosing Node.js)
Points to consider:
I am sure Python, Ruby and all will have a great future. Will Node.js enjoy the same too? Do you think? (long-term plans)
Availability web frameworks: Is there a framework for Node.js that is as mature and complete as Django (or Pylons)?
Availability of support from SO community and the web: that is, can I be sure that I would get a few good replies from the SO community if something goes wrong and I need help? I mean, I am sure that i would, if it is Python, C/C++ etc.
is Node.js too slow to code than Python?
Why I am even thinking about Node.js?
I've read comments/answers on SO saying that Node.js is much much faster than other high-level languages like Python, Ruby or PHP. Sorry, but like I said, it's not my opinion [READ].
If I choose Node.js, I would only have to learn one programming language basically - - JavaScript. (I am not looking for a job, I want to develop a (large?) web application like a social network or photo-sharing service)
[I believe anyone can have these questions, so it's not entirely subjective]

1) I personally love (!) Ruby, I think it's the most beautiful language one can possibly code in, but I also love the speed of Node.js and JavaScript. Fortunately I can combine what I love about the two, the answer is CoffeeScript (it has a Ruby / Python style of programming, but it compiles to plain JavaScript). Note: you should learn JavaScript properly and only then pass to CoffeeScript.
2) I wouldn't use PostgreSQL, because I would like use something more "speedy" like MongoDB (JavaScript on the DB also - it's easier to learn MongoDB than CouchDB if you only know SQL) or CouchDB (which is a pretty amazing db, also in JavaScript - it supports synchronization by default). However if you want to use PostgreSQL there are drivers for it.
3) It's great that you are planning on learning C/C++, since every language is built on top of that. You could write C/C++ modules for Ruby, Node or Python.
Answering your (extra) 3 points:
1) There is a really good web framework called Express, which is highly inspired by Sinatra (Ruby). There are also other frameworks, but I believe Express is the best there is (you can even build your own framework on top of it etc, it's "flexible").
2) I am actually subscribed to the "node.js" tag on SO and I can say that if you post a valid question you'll get an answer from 1 minute to 24h. More than that, just join the IRC channels for Node ( #node.js #express #socket.io #nodejitsu ) and checkout the activity over there. I can assure you while I was learning, I didn't have any unanswered question (for real, the guys are extremely helpful).
3) No, that's not the case once you get used to it. The only thing you need to get used to when coding in Node.js (not only, Erlang, Twisted or EventMachine also) is the asynchronous way of programming. Also there are a ton of modules and helpers for almost everything (so that can speed up your coding too, you don't have to reinvent the wheel for everything - you can also use some JS code for the frontend).
I can tell you from my own experience that once you get used to the async style of programming (with callbacks etc) there's nothing that can slow you down anymore.
Extra
While Node.js is kind of young (2009), Github, Linkedin, Yahoo, 37signals, Learnboost, Trello are using it, so you won't be that brave :P

Dive into Django right after scratching the surface of of Python, good choice?

Little bite background: I joined a software company three years ago after graduated with art degree. It is fair to say I had not touched any code and never thought of that program thing before I joined the software company.
At the software company I dabbled into HTML, CSS, JS and SQL, and it turned out learning those languages were not so hard at all. I lean these languages just for developing apps or web site to see how it works, not for the sack of money or career. I just simply curious, and when I play with those language it makes me fell good, very good. I have built my own static web site, and now I am directing our web developers. now I want to lean something more powerful which could help me understand how dynamic web site works
Hanks to SO, I lean that Python is a very good language for people like me, and I spend couple of months to read and write some simple code when I get home from work. Printing "hello world" or slicing data or writing if a then b if c then d does not give me any felling of achievement. That is why I have picked Django up, which so far is more interesting than Python. I have wrote poll app, blog, photo app etc. by following tutorials.
As I expected, now I feel my python knowledge is limited and it hinders my further explore.
I need your help!
RECAP
No CS background, just arts
Do not have much time, have to work more than 8 hours
Just want to lean web development
Medium knowledge of JS and SQL, good command of HTML and CSS.

It's a great choice. I might even argue it's a great way to learn python, because the documentation for Django is so amazing, and the path to progress so clear-cut and defined, that it keeps things interesting as well as structured.
I learned python on django, with no python/CS background as well. At first, I couldn't tell the difference between python and django :) I say the fit is even better with some experience with HTML/CSS/JS/SQL, as that's ultimately what you are producing with Django.
Learning Python is a rather open ended idea, and the applications of that knowledge require much more understanding than using a framework to build highly functional code that's at first, mostly the framework doing the work and perhaps a few lines of your own code.
Update: to adress your time problem and your direct goal of learning web development beyond static HTML/CSS, I can't think of anything faster than running django (particularly with your background): http://docs.djangoproject.com/en/dev/intro/tutorial01/
There are python web frameworks where you can launch a page, including installation, in about 10 total lines of code but none will match the docs of django.
http://webpy.org/
http://denied.immersedcode.org/ (1 large .py file with all dependencies inside)
I think the alternatives won't be a good tool to learn python but a useful tool once you're comfortable with python.

Architecting from scratch in Python: what to use?

I'm lucky enough to have full control over the architecture of my company's app, and I've decided to scrap our prototype written in Ruby/Rails and start afresh in Python. This is for a few reasons: I want to learn Python, I prefer the syntax and I've basically said "F**k it, let's do it."
So, baring in mind this is going to be a pretty intensive app, I'd like to hear your opinions on the following:
Generic web frameworks
ORM/Database Layer (perhaps to work with MongoDB)
RESTful API w/ oAuth/xAuth authentication
Testing/BDD support
Message queue (I'd like to keep this in Python if possible)
The API is going to need to interface with a Clojure app to handle some internal data stuff, and interface with the message queue, so if it's not Python it'd be great to have some libraries to it.
TDD/BDD is very important to me, so the more tested, the better!
It'll be really interesting to read your thoughts on this. Much appreciated.
My best,
Jamie

Frameworks
OK, so I'm a little biased here as I currently make extensive use of Django and organise the Django User Group in London so bear that in mind when reading the following.
Start with Django because it's a great gateway drug. Lots of documentation and literature, a very active community of people to talk to and lots of example code around the web.
That's a completely non-technical reason. Pylons is probably purer in terms of Python philosophy (being much more a collection of discrete bits and pieces) but lots of the technical stuff is personal preference, at least until you get into Python more. Compare the very active Django tag on Stack Overflow with that of pylons or turbogears though and I'd argue getting started is simply easier with Django irrespective of anything to do with code.
Personally I default to Django, but find that an increasing amount of time I actually opt for writing using simpler micro frameworks (think Sinatra rather than Rails). Lots of things to choose from (good list here, http://fewagainstmany.com/blog/python-micro-frameworks-are-all-the-rage). I tend to use MNML (because I wrote parts of it and it's tiny) but others are actively developed. I tend to do this for small, stupid web services which are then strung together with a Django project in the middle serving people.
Worth noting here is appengine. You have to work within it's limitations and it's not designed for everything but it's a great way to just play with Python and get something up and working quickly. It makes a great testbed for learning and experimentation.
Mongo/ORM
On the MongoDB front you'll likely want to look at the basic python mongo library ( http://api.mongodb.org/python/ ) first to see if it has everything you need. If you really do want something a little more ORM like then mongoengine (http://hmarr.com/mongoengine/) might be what you're looking for. A bunch of folks are also working on making Django specifically integrate more seamlessly with nosql backends. Some of that is for future Django releases, but django-norel ( http://www.allbuttonspressed.com/projects/django-nonrel) has code now.
For relational data SQLAlchemy ( http://www.sqlalchemy.org/) is good if you want something standalone. Django's ORM is also excellent if you're using Django.
API
The most official Oauth library is python-oauth2 ( http://github.com/simplegeo/python-oauth2), which handily has a Django example as part of it's docs.
Piston ( http://bitbucket.org/jespern/django-piston/wiki/Home) is a Django app which provides lots of tools for building APIs. It has the advantage of being pretty active and well maintained and in production all over the place. Other projects exist too, including Dagny ( http://zacharyvoase.github.com/dagny/) which is an early attempt to create something akin to RESTful resources in Rails.
In reality any Python framework (or even just raw WSGI code) should be reasonably good for this sort of task.
Testing
Python has unittest as part of it's standard library, and unittest2 is in python 2.7 (but backported to previous versions too http://pypi.python.org/pypi/unittest2/0.1.4). Some people also like Nose ( http://code.google.com/p/python-nose/), which is an alternative test runner with some additional features. Twill ( http://twill.idyll.org/) is also nice, it's a "a simple scripting language for Web browsing", so handy for some functional testing. Freshen ( http://github.com/rlisagor/freshen) is a port of cucumber to Python. I haven't yet gotten round to using this in anger, but a quick look now suggests it's much better than when I last looked.
I actually also use Ruby for high level testing of Python apps and apis because I love the combination of celerity and cucumber. But I'm weird and get funny looks from other Python people for this.
Message Queues
For a message queue, whatever language I'm using, I now always use RabbitMQ. I've had some success with stompserver in the past but Rabbit is awesome. Don't worry that it's not itself written in Python, neither is PostgresSQL, Nginx or MongoDB - all for good reason. What you care about are the libraries available. What you're looking for here is py-amqplib ( http://barryp.org/software/py-amqplib/) which is a low level library for talking amqp (the protocol for talking to rabbit as well as other message queues). I've also used Carrot ( http://github.com/ask/carrot/), which is easier to get started with and provides a nicer API. Think bunny in Ruby if you're familiar with that.
Environment
Whatever bits and pieces you decide to use from the Python ecosystem I'd recommend getting to who pip and virtualenv ( http://clemesha.org/blog/2009/jul/05/modern-python-hacker-tools-virtualenv-fabric-pip/ - note that fabric is also cool, but not essential and these docs are out of date on that tool). Think about using Ruby without gem, bundler or rvm and you'll be in the right direction.

Ok, you might be making a mistake, the same one I made when I started with python.
Before you decide on a thing like django, which is an excellent, yet atypical python web framework, spend an night cuddled up with:
This, is a good start. Make sure you do A little Werkzeug watching , Then check out
some classic WebOb. Maybe, if you feel the fire in the blood, and you might, wsgi is a bit flawed, but only to the gods, check out Flask
I'm not saying use it, Django is beautiful too, but if you don't know python, and you go through django, you run the risk of learning a framework.
WSGI is super straightforward. You'll find out about Paste, and Pastescript, and Pylons.
Then, make your decision. It'll be much easier learning stuff doing bare bones wsgi or Flask, stuff like variable assignment, using the interpreter, style concerns, testing, on 3 files for a couple of nights, instead of django. Take 2 nights. Then you'll see the great similarity between python web frameworks, instead of the differences. Hell, you might even roll with Flask.
Just some advice, I did the same thing with ruby, going in through Rails, and... well, strong words were said.
Language, then basic wsgi and testing, then pick your framework and roll

I'm new to python myself, and plan to get more in depth with it this year. I've had a few false starts at this, but always professional needs bring me back to PHP. The few times I've done some development, I've had really good experiences with web2py as a python framework. It's quite well done, and complete in features, while still being extremely lightweight. The database layer seems to be very flexible and mature.
As for TDD/BDD and the rest of your questions, I don't have any experience with python options, but would be interested to hear what others say.

I am using Twisted Framework based Nevow library for python based web app.
All your criteria fit into this single framework.

What are the benefits of using Python for web programming?

What makes Python stand out for use in web development? What are some examples of highly successful uses of Python on the web?

Django is, IMHO, one of the major benefits of using Python. Model your domain, code your classes, and voila, your ORM is done, and you can focus on the UI. Add in the ease of templating with the built-in templating language (or one of many others you can use as well), and it becomes very easy to whip up effective web applications in no time. Throw in the built-in admin interface, and it's a no-brainer.

Certainly one successful use of Python on the web is Google App Engine. Site authors write code in (a slightly restricted subset of) Python, which is then executed by the App Engine servers in a distributed and scalable manner.

Quotes about Python:
"Python is fast enough for our site
and allows us to produce maintainable
features in record times, with a
minimum of developers," said Cuong Do,
Software Architect, YouTube.com.

YouTube uses a lot of Python and is probably the best example of a Python success story.
A great example of a Django success story is the Washington Post, who recently shared a big list of applications they have developed:
http://push.cx/2009/washington-post-update
www.lawrence.com and www.ljworld.com are two of the first sites to use Django (before it was even open source).
djangositeoftheweek.com has a bunch of good case studies.
www.everyblock.com is another great example.
Finally, http://www.djangosites.org/ links to nearly 2,000 other Django powered sites.

Short anwser: the diversity of tools readily available and freedom of choice.
This sounds like a simple question but which it really isn't. While Python is very good for web development and this has been shown by the, oh so famous, Google App Engine, Plone and Django. One has to point out that the development way in Python requires a lot more from the developer than PHP but it gives a lot more to the mix as well.
The entry level on actually producing something is higher. This is because there are bunch of different tools for doing web development with Python. Choosing the web development framework can be a hard decision for an inexperienced developer.
Having a lot of different tools is a two edged sword. To some extent it brings you the freedom of choice to pick the one you might want but then again how do you really know which one is good for what you're doing. This brings me to my point. Python stands out from the mass by not having a standard or de facto web development library. While this is pretty much against the principle of having only one simple way of doing on thing it also brings us a wide variety of different tools with different kind of design choices. At first this might feel very frustrating because it would be so much easier if somebody had made the choice for you but now that you're left to make the choice you actually might have to think about what you're doing and what would fit. ...or you might just end up picking one and blowing your head off after you've realized that you made the wrong choice. Anyway you end up, you've made the choice and no one else.

Furthermore,
Python is both strong in web and in data analytics and machine learning. For example scikit, sci-py and numpy are very strong. In some cases, it can be very interesting to have the both elements on the same server.
For example http://rankmytweet.com uses this a lot.

trac(bug tracker) and moinmoin(wiki) are too web based python tools that I find invaluable.

GNU Mailman is another project written in python that is widely successful.

As many have pointed out, Django is a great reason to use Python...so in order to figure out why Python is great for web development, the best bet is to look at why it is a good language to build a framework like Django.
IMHO Python combines the cleanest, or at least one of the cleanest, metaprogramming models of any language with a very pure object orientation. This not only makes it possible to write extremely general abstractions that are easy to use, but also allows the abstractions to combine relatively cleanly with others. This is harder to do in languages that take a code-generation based approach to metaprogramming (e.g. Ruby).

Dynamic languages are in general good for web apps because the speed of development. Python in particular has two advantages over most of them:
"batteries included" means lots of available libraries
Django. For me this is the only reason why i use Python instead of Lua (which i like a lot more).

Besides the frameworks...
Python's pervasive support for Unicode should make i18n much smoother.
A sane namespace system makes debugging much nicer, because it's typically easier to find where things are defined.
Python's inability to function as a standalone templating language should discourage the mixture of HTML with model code
Great standard library

Other examples of Python sites are Reddit and YouTube.

Why does Ruby have Rails while Python has no central framework?

This is a(n) historical question, not a comparison-between-languages question:
This article from 2005 talks about the lack of a single, central framework for Python. For Ruby, this framework is clearly Rails. Why, historically speaking, did this happen for Ruby but not for Python? (or did it happen, and that framework is Django?)
Also, the hypothetical questions: would Python be more popular if it had one, good framework? Would Ruby be less popular if it had no central framework?
[Please avoid discussions of whether Ruby or Python is better, which is just too open-ended to answer.]
Edit: Though I thought this is obvious, I'm not saying that other frameworks do not exist for Ruby, but rather that the big one in terms of popularity is Rails. Also, I should mention that I'm not saying that frameworks for Python are not as good (or better than) Rails. Every framework has its pros and cons, but Rails seems to, as Ben Blank says in the one of the comments below, have surpassed Ruby in terms of popularity. There are no examples of that on the Python side. WHY? That's the question.

As I see it, Rails put Ruby on the map. The simple fact is that before Rails, Ruby was a minor esoteric language, with very little adoption. Ruby owes its success to Rails. As such, Rails has a central place in the Ruby ecosystem. As slim points out, there are other web frameworks, but it's going to be very difficult to overtake Rails as the leader.
Python on the other hand, had a very different adoption curve. Before Rails, Python was much more widely used than Ruby, and so had a number of competing web frameworks, each slowly building their constituencies. Django has done a good job consolidating support, and becoming the leader in the Python web framework world, but it will never be the One True Framework simply because of the way the community developed.

I don't think it's right to characterise Rails as 'the' 'single' 'central' Ruby framework.
Other frameworks for Ruby include Merb, Camping and Ramaze.
... which sort of invalidates the question.

The real technical answer is that there are three major approaches to web-development in Python: one is CGI-based, where the application is built just like an old one-off Perl application to run through CGI or FastCGI, e.g. Trac; then there is Zope, which is a bizarro overengineered framework with its own DB concept, a strange misguided through-the-web software development concept, etc. (but Plone is still quite popular); and then there is Django (and Turbogears, etc.), which is guided by the same just-the-tools-needed philosophy as Rails (it can be argued who got there first or who did it better). A lot of people would probably agree that the Django/Rails/CakePHP approach is better than the older approaches, but as the older language Python has a lot more legacy frameworks that are still trying to evolve and stay relevant. These frameworks will hang on because there is already developer buy-in for them. For example, in hindsight many people would probably say that Zope (especially ZODB) was a terrible mistake, but Zope 3 is much better than Zope 2, and there are already whole companies built around Zope technologies.

Rails was somewhat revolutionary in its extreme "convention over configuration" approach which set it apart from pretty much anything else and made it the "killer app" of Ruby, causing a lot of people to notice Ruby in the first place.
So the question is really "Why did David Hansson decide to write Rails in Ruby rather than Python?"

Remember that Ruby had existed for a long time before Rails was created. According to Wikipedia, Ruby was created in the mid-90's; Rails didn't come around until 2004. Ruby is simply the language that David Hansson chose to use for Rails.
And yes, I would say Ruby is to Rails as Python is to Django.

I agree with Ned. I'd bet that more than 90% of Ruby installations are for no other purpose than running Rails. Rails dominates Ruby - there is no single application that dominates Python, mainly because the Python community is somewhat bigger than the Ruby community.

Would ruby be less popular without Rails? absolutely.
Would Python be more popular with one true framework? You mean as opposed to several? May be, who knows. In any case most agree Django is a very good framework.
Why, historically, did it happen to Ruby? Because DHH chose Ruby after doing his own research.
To add to the answer regarding Rails having made a breakthrough because of 'convention over configuration' there is also another reason and that is that Rails has been using the meta-programming abilities of Ruby superbly. A lot of the magic of Rails which has contributed to removing a lot of the pain of developing web apps came through this clever use of ruby meta-programming.

I'd have to agree that Django is basically the "Rails for Python" equivalent. Why did it take so long? The simple answer is too many options.
In Python, there are many request/response systems, url rewriters, ORMs, templating languages, etc. that you could build a web stack in dozens of different configurations. In fact, this is exactly what Pylons and TurboGears do is provide a reliable, predictable stack to build MVC web apps.
What Django did differently was they encapsulated everything. Rather than go the components route, they built one contiguous system. They built their own ORM, their own template language, their own middleware system, etc. Their reasoning was that there was no unified system like this for Python.

Python is not a one-trick pony. Therefore, there's no single "central framework" for it. Many people first heard of Python as "another nice OO language" or through one of the many uses to which it has been put.
To be fair, Ruby is not a one-trick pony either. It's just that many people regarded Rails as the "killer app" that got them to look at a previously-not-well-known language. I suspect many people never heard of Ruby before Rails, but that's by no means the only thing Ruby can do.

If you followed the news, you have read that Merb and Rails will merge. This is a good move IMHO. I think it's because of the common goal that the developers have: They want a simple framework for webdev, which comes with a OR mapper, routing, template language, etc which fits for most tasks..

Check out this article on why we'll never see Python-on-Rails. The author gives some of the basic reasons why Python has never had and will never have a central framework. I might add, myself, that Java doesn't have one either, and for the same reasons.
According to the author, Rails is strictly tied to its "implementation," which is Ruby. Rails was adopted by many developers and Ruby was just part of it. Rails works perfectly on Ruby (or Ruby wanna-bes like Groovy), but more importantly, as many other answers say, Rails led the way to Ruby adoption.
This is why Rails-for-Python won't
work, or at least what people have
been focusing on with Rails isn't
correct. It's not about the
implementation or the quality of the
framework, it's about the pattern of
adoption. It's about putting the
framework up front, and the
implementation in the back -- even if
this wasn't the Rails developers
intentions (though maybe they are
clever and this was their intention).
Basically, you can't get a bunch of language-loving folk to gather around a single framework. On the Java side, while Spring is well-loved, it's no Rails in terms of popularity in the Java community. In a mature community developers have their own ideas about what metaphors work and don't work in a framework. This is why Rails leads to Ruby and not the other way around (typically, mostly, not in all cases).