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TurboGears: Python on Rails?
gcantallopsr writes "If you liked Ruby on Rails and its 15m intro video (.mov) you will probably like TurboGears and its 20 minute wiki tutorial. (.mov) It shows you the development of a simple wiki in just 20 minutes, and there is a text version of the tutorial. TurboGears uses Python, SQLObject, CherryPy, Kid, MochiKit and some extra pythonic glue to help you to (in their own words) 'Create a database-driven, ready-to-extend application in minutes. All with designer friendly templates, easy AJAX on the browser side and on the server side, not a single SQL query in sight with code that is as natural as writing a function.'"
How do the python crowd expect to get taken seriously when implementing a wiki takes an whopping 125% as long in python as in ruby!!!!!!????
;-)
(oh wait, they did ajax as well..
Official GOD FAQ.
Why is this an advantage?
I've used Python/SQLObject/CherryPy on a project before. It's very quick to code something useful. SQLObject will change the way you think about how you integrate DBs to web applications. All in all, it's well worth checking out.
What software do people use for making these neat videos? (I realise this is bordering on off-topic :) )
Believe with me, my saplings.
One of the nicest features of SQLObject is that it insulates you from the peculiararities of the database's SQL syntax, so you don't need to put any SQL code directly into the Python code (but you can if you need to for efficiency or if you're willing to write non-portable code).
The SQL database abstraction layer is an important feature of SQLObject, that Ruby on Rails doesn't currently support -- you have to write database dependent SQL code mixed in with your Ruby code.
SQLObject lets you write generic SQL queries with normal Pythonic expressions and operators, which are automatically translated into the database dependent SQL syntax by the database driver. So you don't have to change any of your Python code to port it to a different database, and you don't have to mix together two different notations, or quote a bunch of SQL strings in your Python code. It's a much more "pythonic" way of database programming than raw SQL.
The great thing is that it's so convenient and the syntax is so simple, that you can use the interactive Python shell to browse and test out and edit your database. It's trivial enough to type in some Python code on the keyboard that loops over the results of a query, performs some complex logic, and validates and edits a bunch of rows in the database. Much more powerful and easier to use than anything you can do with raw SQL.
-Don
Take a look and feel free: http://www.PieMenu.com
Ok, so some of these tools are not suitable for running Amazon. But guess what - most people are not running Amazon! A lot of people don't have the development resources that amazon has, either, so what they are really looking for is a sweet spot that lets them get going quickly, and will grow within reason.
I'm still mulling it over and working on it, but I talk some about "scaling down" in this article:
http://dedasys.com/articles/scalable_systems.html
You're right of course that you don't want stuff that falls over the first time traffic spikes a bit, but you absolutely must have something that you can use to produce a functional product. You can have the fanciest, most scalable system out there, but if you spend two months twiddling with XML config files, things just aren't going to work out.
http://www.welton.it/davidw/
I'm definitely not an expert in Python, in fact I've only ever given it a cursory look. However that tutorial was damn impressive. Obviously he had some prior knowlege of Python and using TurboGears but it is really not all that difficult to build something like a Wiki using that framework. As far as web work I've slowly become disenchanted with PHP. It's a good language to be sure but it's simplicity is short-lived. As you want to do more complex things you end up having to work around PHP more than you get to benefit from it. A large web project in PHP ends up structured like a project of similar size in Perl or Python. Between TurboGears on Python and Ruby on Rails it looks like I have some reading to do.
I'm a loner Dottie, a Rebel.
if you want to do something for your professional career, don't waste your time with those kind of frameworks.
If you want to do something for your professional career, get familiar with as varied a collection of tools as you can. Know the pros and cons of each. Actually test their performance, make toy projects, steal ideas and patterns. Be opinionated, but prepared to honestly choose the best tool for the job you're given, and to explain why it is the best, to suits and to techies. A few hours getting to know something new is never wasted.
I believe posters are recognized by their sig. So I made one.
Tried TurboGears, but the fact that it's a glue was way too appparent. I then moved on to trying Django and fell in love. All the stuff TurboGears can do Django can too, but natively.
If you're up for small Wikis, there's always HeyHeyWickie, a Python Wiki in under 4K lines of code (using EmPy and docutils).
Also worth checking out: Twisted. I haven't had occasion to use it myself, but people I know swear by it.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
Whilst Rails is an excellent framework for web applications, I've found that it gets exponentially more difficult to work with when your database structures grow more complex than interconnected lists. I recently designed a double-booked accounts program in Rails, and whilst most of the code was simple to design, I quickly got bogged down in handling the accounts-tree and the double-booking of financial records. Here the documentation ran out, and I was forced to go through the Rails source to discover a solution to my problem, which turned out to be less than optimum.
Secondly, whilst I have done a fair bit of work in Ruby, I can't help but prefer Python. If there's little difference between Rails and, say, Turbogears, Django or Subway, then surely it comes down to personal preference. Python web frameworks appear to take a more piecemeal approach than Rail, which can provide a more flexible solution in certain situations.
Can't say I much like SQLObject's syntax, though; but CherryPy seems rather elegant.
Yeah, that's the part that gets me wondering. People keep talking about hiding away the SQL. But if they don't want SQL, then why are they using an SQL RDBMS in the first place?
;) ), rather than it being neatly stored with 1000 other nonrelated SQL statements (as functions or otherwise).
Shouldn't they be using something else then? Otherwise they'll get the drawbacks of using an SQL database but fewer of the advantages. What happens if performance in a particular area is not good enough?
Say you want to store a session in a database and you want it to expire after X seconds of inactivity.
A simplistic method would be to update the session row each time there's activity. But this would cause lots of writes which would be slower in most proper databases (those that actually write to disk for writes). An alternative would be the databases equivalent of "update sessiontable set lastactive=now() where sessionid='$sessionid' and lastactive+'1 second' <= now()".
With this, you could have thousands of hits per second but only 1 forced write to disk per second due to that query.
How would you achieve this when you're so abstracted away from the SQL database? And it might look strange to others when you try to do the same thing N layers above the database. I'm sure there are better examples.
Those sort of queries are likely to look different on different RDBMSes. You could make a function that looks the same, but someone still is going to have to write the SQL for portability (and sometimes bad luck, it's not possible - DB doesn't support functions or that sort of function). Also, if only the program's session module does that stuff, then what's so bad about leaving the SQL in there? At least then there'll be some context to understand the SQL (and whether it's wrong or right
Sure it's ugly. But if people want it all so elegant and clean maybe they should write _everything_ in some version of Lisp, and not interface with the rest of the ugly real world.
yeah, Maypole and Catalyst.
"...we should just trust our president in every decision that he makes and we should just support that." B.Spears 2003
> For anything substantial, though, it always seem to wind up
> being more work as I figure out how to configure & trick the
> persistance layer into giving me my data in the most efficient
> way. This can be frustrating when you know how to accomplish
> the same thing in 5 seconds using plain SQL. Maybe it's just me?
That raises a question about these persistence layers. Most of the tables we create use an "always insert, never update or delete" model so we can keep track of who made the change, when the change was made, and by whom.
You have to code, normalize, index, and select from these tables in a particular way otherwise you'd end up with extremely inefficient code. I just don't see how a persistance layer can handle this.
Another thing, one thing I've learned is that for enterprise applications, data outlives the application and in many cases, it predates the application. In essense, the persistence layer will need to be retrofitted into the application. Top-down GUIs like the ones presented for Rails appear to be of no use. We already know the exact representation of the data so Rails will need to work from the bottom up by default.
As a side note, I don't see why people are so afraid of a little SQL. Sure it takes time to learn how to master efficient SQL coding, but it's well worth it. It's the most efficient way to deal with most data, and because it's a declarative language, it's often more intuitive than the imperative language you're working in. It's also supported by most languages, so it's universal. If you're using a strict model-view-controller paradigm, database access will be restricted to the model and recast into data objects that can be used by the view and controller. If done correctly, you can rewrite the data code of several applications every day of the week without affecting the view and the controller (i.e. the bulk of your code). From what I've seen, that clarity of what exactly is happening and how complex things are mapped really helps with maintenance and optimization. From trying to maintain persistense layers, I'm left trying to figure out "what on earth is the persistense layer trying to do that is causing so much trouble".
Rails has taught us some important lessons, but they aren't really technical lessons:
After looking at various pieces of Rails, these lessons have stood out to me, but the particular technology in Rails has not. Sure, there are some good ideas, but nothing radical, and there's good ideas everywhere waiting to be mined. We're not beneath mining other people's ideas, but it does not follow that the result is merely a "replication" in part or in whole.
As for Ruby: I think the two languages are largely equivalent in terms of what you can do. I would not say the same about PHP or Java. As for Rails specifically, I think it is only ahead of Python options in the second derivative. With conscious players the second derivative doesn't mean a whole lot.
A few hours getting to know something new is never wasted.
I once spent a couple of hours looking at VBScript.
I think I came away knowing less about good programming than before, *and* I was out two hours.
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