15 ms·

I only know PHP. How do I write a Web application in Python?

230 points by jrheard 14y ago

prezjordan 14y ago
off-topic: love the greek-lettered ordered list.
gcb 14y ago
Say wat you want of php. But it's (insert personal pejorative option) made for it. Sure Its a_little_inconsistent AndSomewhatChaotic But all the basics for the web are incredible accessible right away. With every other language you have to start with a framework. I find php easier than rails to prototype applications and do fast hacks that need a web face. It's simply the right tool for the job on those occasions. Of course, later they become huge systems...
- eevee 14y ago
  That's why e.g. Flask exists: it gives you the basics, plus light structure and templating and routing and XSS protection and deployment options and whatever else. With no setup and no boilerplate. It's about as much effort as typing `<?php`.
  - chrisguitarguy 14y ago
    While that's true (and I do love Flask), PHP comes installed on every discount web host. Deploying a PHP app is as easy as using FTP, deploying a Python app can be -- but doesn't have to be -- complex. I'd say this is the bigger sticking point than the framework. Obviously Heroku and other PAAS providers are changing the game as far as deployment ease. It should be to see what happens in the next few years on that front.
    - espeed 14y ago
      Deploying a PHP app is as easy as using FTP, deploying a Python app can be -- but doesn't have to be -- complex. Easy != Simple && Easy != Good See "Simple Made Easy" (http://www.infoq.com/presentations/Simple-Made-Easy http://www.infoq.com/presentations/Simple-Made-Easy).
    - eevee 14y ago
      It's a chicken-and-egg problem. Best I can do is encourage more people to write more Python software, so those crappy free hosts are more inclined to support running it. Until then, I don't think it's terribly unreasonable to pay twenty bucks a month for a server to play with. That's less than AT&T wants to charge me for sending a thousand 160-byte messages.
      - joering2 14y ago
        "crappy free hosts" ?
      - espeed 14y ago
        Don't mess with "crappy free hosts" -- just run it on a free Heroku dyno (http://www.heroku.com/pricing http://www.heroku.com/pricing). Kenneth (http://kennethreitz.com http://kennethreitz.com) shows you can get good performance with Flask on the free dyno (http://flask.pocoo.org/mailinglist/archive/2012/2/22/flask-on-heroku-%2B-gunicorn-static-files/#cff05916ae6854557b93d0226cb87151 http://flask.pocoo.org/mailinglist/archive/2012/2/22/flask-o...).
        eli 14y ago
        That's a fair bit more involved than "FTP files to my web host and they usually just work"
        espeed 14y ago
        It's actually easier... $ git push heroku master
        eli 14y ago
        Sure, well I would hope it's easy to do a one line deploy to any platform and with any language... once you set it up. You left out freezing requirements for pip, setting up cedar, etc. Nothing like that for a simple PHP app. I don't want to overstate the case; deploying Flask isn't hard, but deploying PHP is stupidly easy.
- BrandonM 14y ago
  That's a nice sentiment that's completely inaccurate. Even 6 years ago when I first started programming Python, simple Python cgi scripts were very easy to write. It's as simple as: print """\ Content-type: text/html <html>...</html>""" With %(var)s interpolation, you can even slap in locals() easily to trivially put variables' values into the page.
  - eli 14y ago
    That doesn't seem like it will scale very well at all. Or am I missing something?
    - justincormack 14y ago
      PHP doesn't scale well either. You can rewrite for scaling later.
  - gcb 14y ago
    and you think that manually handling headers is more straightforward than php? I disagree.
    - BrandonM 14y ago
      "Manually handling headers"? That is how people wrote websites in the early 2000s. Many cgi scripts were cobbled together in Perl. I found that I liked Python better. I understand that in PHP you just add some <?php ...> stuff to an otherwise normal HTML file, but the situation in Python, with its multiline strings that support variable interpolation, isn't much worse. Just add the lines I mentioned to the top (treat is as a recipe if you like), and the rest is better than PHP.
akkartik 14y ago
What's wrong with mysql?
- cbg0 14y ago
  Apparently, it isn't PostgreSQL; If you have no need for Postgres features and you're not familiar with it, sticking to MySQL is fine.
  - gbog 14y ago
    Well you can say the same for windows vs Linux or visual basic vs any other language, and you can also continue using paper glue to attach paintings on the wall. It is not a matter of what you need, it is a matter of using good tools that will help you do good work, understand better what you do, build durable products, and so on. Just one example: MySQL will not complain if you add a check constraint but will not actually add it to your schema. That's a very Microsoft-y way to handle things, and should give cold sweat to any coder.
    - cbg0 14y ago
      This is actually documented behavior: "The CHECK clause is parsed but ignored by all storage engines." From: http://dev.mysql.com/doc/refman/5.5/en/create-table.html http://dev.mysql.com/doc/refman/5.5/en/create-table.html I believe it was left to support certain migrations(?). You can create a trigger instead. I'm pretty certain many people will consider MySQL a good tool with which they produce good work. While it may have its quirks, it's present on virtually all shared hosting environments, just like PHP, so it's very easy to create and deploy an application powered by both these technologies.
      - gbog 14y ago
        So, you are telling me that it is a good thing, a normal behavior for a reliable tool to just ignore instructions I send to it and do nothing with it, not even a warning? So when I migrate a database, I have to carefully check each and every instructions (schema and data) and make sure MySQL did not "decide" it was not worth it and just silently threw it by the window? I have hard time to believe you are serious here...
ashray 14y ago
This guy failed to cover web.py which is one of the fastest ways to start prototyping a web app in python. =/ http://webpy.org/ http://webpy.org/ I personally use it for a small app which returns (and stores) search suggestions from redis.
gbog 14y ago
"MySQL is the PHP of databases". Strange, I just had this sentence popping in my head yesterday. I'm seriously considering writing a list of its wrong doings. Great article overall.
- jrheard 14y ago
  I'd be interested in reading that list!
- AgentConundrum 14y ago
  Please write that list. I'd be very interested in reading it.
- glogla 14y ago
  Color me as another interested specimen.
  - gbog 14y ago
    I wanted to do that now but did some lego with my kid instead, will keep you 3 informed when done.
    - gbog 14y ago
      It seems an article on Ars Technica has already compiled some defect of MySQL: http://arstechnica.com/civis/viewtopic.php?f=20&t=92525 http://arstechnica.com/civis/viewtopic.php?f=20&t=92525 Another thing that reminds of PHP, the list of commands: mysql mysql_client_test_embedded mysql_find_rows mysqlrepair mysql_tzinfo_to_sql mysqlaccess mysql_config mysql_fix_extensions mysqlreport mysql_upgrade mysqladmin mysql_convert_table_format mysql_fix_privilege_tables mysql_secure_installation mysql_waitpid mysqlanalyze mysqld mysqlhotcopy mysql_setpermission mysql_zap mysqlbinlog mysqld_multi mysqlimport mysqlshow mysqlbug mysqld_safe mysql_install_db mysqlslap mysqlcheck mysqldump mysqlmanager mysqltest mysql_client_test mysqldumpslow mysqloptimize mysqltest_embedded Why the hell show we want a 'mysqldumpslow'? Is it because mysqldump is fast but wrong? And why not mysql_dump? I have started with MySQL for my first (php) website, and to me the database was just the natural storage, I had no idea of the problems, because I didn't know that a relational database is a particular well-defined mathematical object, which asserts truths about the "world" in a manner that makes it possible to model this world safely and ask questions about it. Then I used PostgreSQL at my previous work, and discovered it all, the hard way. And PostgreSQL has (almost) always been a reliable companion taking care of the most valuable asset: the Data. Then I switched job and have to use MySQL again. I live with it, it's fine, but the difference is not benign, and I sometime wonder if the NoSQL movement is not a partly a misunderstanding and should renamed NoMySQL: when using an unreliable datastore, it is certainly better to use one that is explicitly not reliable and do not force on you the relational model while, at the same time, not giving you its strengths.
Xuzz 14y ago
I'd say the necessity of this post is why PHP is as popular as it is. With PHP, there are no package managers I have to install; there is no template language to learn; there is often no version control; there is no "framework"; etc. You just drop in a .php file and, most likely, it will just run. If I need a quick dynamic page on my server, it's much easier to do this in PHP than in Python or Ruby. Until Python or Ruby have that kind of simplicity, they can't overtake PHP. While it might not be the kind of design that leads to well-designed web apps or even good code, it is the kind of design that leads to more — especially less technical, or, like me, lazy — users. It's up to the developers of those languages if this is even a market they want. There may need to be something new to do the same job as PHP, but better, without the innumerable warts.
- eevee 14y ago
  Most of the post _isn't_ strictly necessary. You don't need a database to get your feet wet. You don't need to care about XSS for your first throwaway app (though, arguably, you should). I pimp Mako precisely because there's no separate language to learn: the core syntax is just Python. I tried to describe the _ecosystem_, and I assume any serious PHP application will care about most of the same things. Here's all you really need: look at http://flask.pocoo.org/ http://flask.pocoo.org/ and do that thing it says right there. You don't even need to install a separate web server. (Yeah, yeah, 5.4, I know.) A "quick dynamic page" is a deployment problem. If you're already running Apache and mod_php, you already have an environment ready to go to serve PHP, so of course it'll be easy for you. I don't run Apache, so PHP doesn't really help me there. (mod_passenger promises to, but I haven't tried it with Python yet.)
  - lloeki 14y ago
    Also, http://pow.cx/ http://pow.cx/ (Ruby I know, but it shows such things can be done.) Also the argument of python/ruby requiring lots of configuration while php would not is just plain bullshit. Making PHP run with Apache (esp. on a windows machine) without stuff like EasyPHP (and this is where you stop comparing apples to oragnes) is by and large tough on the beginner.
capkutay 14y ago
I like java for web app development, simply because it has a well-structured api and a massive community of developers who have run in to the majority of the road blocks you will most likely encounter on the way to launching your app.
- yolesaber 14y ago
  What frameworks and platforms would you recommend for web development with java? I am writing my senior project at college in java (mainly because of the wide amount of image processing libraries available) and would love to add web capabilities.
  - AlexSerov 14y ago
    http://www.hybridserverpages.com/ http://www.hybridserverpages.com/ Just two days learning curve.
  - cletus 14y ago
    I tend to prefer Python/Flask for Web dev to Python but if you are inclined to use Java there's only really one framework that doesn't make me want to tear my eyeballs out. That framework is Spring MVC. It is DI, adapters for vendor-specific libraries and utility. It's probably not the easiest thing to start with just because it is so flexible that it can be hard to know where to start. A good "Hello World" Spring MVC 3.1 app would go a long way. I really would like to use the Play Framework and it's so close to being great but it just falls too far short. I really liked Play 1.x with Groovy templates. It was simple and it pretty much just worked. Play 2.x has gone in a radically different (and backwards incompatible) direction. It is now part of Typesafe and the goal of Play 2.x is to make Scala a first-class citizen. The problem is that many of the niceties of Play are either harder to use or just outright missing in Java Play 2.x (eg AppEngine support and the OAuth client were all present in 1.x and are slated for a future 2.1 release). There really is a niche for a Java Web framework that like Play ditches the JEE/servlet model in favour of the Rails/Django way of doing things (including dynamic class reloading) but doesn't do it in a way that makes me want to stab myself repeatedly. This would include playing nice with the Java ecosystem (seriously just use Maven and to hell with SBT).
zobzu 14y ago
"I only know PHP" "I just trashed PHP rather harshly" "I want to learn python" Well, you're doing it wrong. How can you trash PHP if you know no other languages ?! You're following articles, posts saying PHP is bad and.. you decide then that's right it's bad! Ever though about thinking on your own first? Like, actually trying a language (python, why not) then deciding if it's better? This kind of stuff always amaze me. You know, sheepish.
- eevee 14y ago
  This is part of an FAQ series. The bolded part ("I only know PHP...") is the question I'm answering. I'll leave you to contemplate the irony here.
yaix 14y ago
Nice littel overview, but... "Unicode sucks. This is a universal truth." And here I stopped reading. Unicode is the best thing around, what sucks it that Py2 does not implement it very well. Py3 does, and that is the main reason I really would like to use it and hope Django will soon fully support it. (Because: there are other languages beside the European ones)
- eevee 14y ago
  Fair point. Correction: working with encodings sucks. Py3 isn't magnitudes better with Unicode; it's better about converting incoming bytes, and it makes literals into real strings. But the former isn't necessarily a good thing, and you can get the latter with a `__future__` import. Always dying on implicit conversions is definitely nice, though.
  - adeelk 14y ago
    Working with encodings is indeed annoying in Python, but it’s not a “universal” problem.
    - anuraj 14y ago
      There is a language called 'Java' where every string is in unicode, and I do not remember ever running into an issue!
      - duskwuff 14y ago
        Except that Java strings aren't in Unicode. They're in UTF-16, which is the worst-of-all-worlds encoding. (It's big and heavy, and it still has multibyte sequences. They're just rare enough that you're likely to forget about them during testing.)
        0x09 14y ago
        UTF-16 is most certainly Unicode, even if it isn't the preferred flavor.
joeycfan 14y ago
Learn Python. It's easy. It's like Internet Fortran.
exim 14y ago
In python, stay away from default arguments for methods/functions. EDIT: yes, mutable default values: http://effbot.org/zone/default-values.htm http://effbot.org/zone/default-values.htm
- espeed 14y ago
  Do you mean don't use defaults that contain mutable values?
achristoffersen 14y ago
I have no idea why web2py gotten such a bad rep. I am a beginning webdeveloper and seriously: web2py is a pleasure to work with. Simple to start, deploy, port and hack. It's backwards compatible and has a template language that really is non existant as so far as its pure python. Compare that to Rails - which is (comparable) hell to set-up and breaks with upgrades etc. If you want python web development to be simple, web2py is the way to go. Since I don't have a CS degree and I have often been wrong before - there might be a real problem somewhere. But I don't think so. One of the reasons for this is that Jakob Moss removed his web2py bashing from this thread. Didn't edit - removed it: https://www.quora.com/Is-web2py-a-good-Python-web-framework/answer/Anthony-Bastardi https://www.quora.com/Is-web2py-a-good-Python-web-framework/...
- irahul 14y ago
  > But I don't think so. One of the reasons for this is that Jakob Moss removed his web2py bashing from this thread. Didn't edit - removed it: https://www.quora.com/Is-web2py-a-good-Python-web-framework/.. https://www.quora.com/Is-web2py-a-good-Python-web-framework/.... What did he remove? https://www.quora.com/Is-web2py-a-good-Python-web-framework/answer/Jacob-Kaplan-Moss-1 https://www.quora.com/Is-web2py-a-good-Python-web-framework/... This isn't the first instance of Django/Flask people not agreeing with web2py design and implementation, and they have been vocal about it a couple of times. http://www.reddit.com/r/Python/comments/ex54j/seeking_clarification_on_pylonsturbogearspyramid/ http://www.reddit.com/r/Python/comments/ex54j/seeking_clarif... Look for comments by mitsuhiko(flask dev) and jacobian(django dev).
  - achristoffersen 14y ago
    Sorry - I remembered that I on an earlier occasion couldn't find JKM' answer. It's there now - and I personally don't find it convincing. Again - I am a novice and has no authority here. – I'd edit above if I could. I am sorry that I wrote wrong info. Thanks for the reddit link. As you say it seems to me most of the flak is from not agreeing on something. But can an oppinion be correct? And yes: Mitsuhiko seems to be a super cool, clever and friendly guy. In my last project I played around with request. Lovely it was. Anyways: my point was not to express that web2py is the greatest thing invented since bacon. Only that I don't understand why the python community dislike it so. After all - web2py makes it very easy to build stuff. Hence it will probably attract people to the language. Hence make it more feasible for webhosts to offer python friendly environments. And that should be a good thing? Especially in the context of OP - "how do PHP guy start with python"?
bobsy 14y ago
I would love to switch to Python from PHP but I can't. The reason is I keep getting told to learn Python 2. Python 3 has been out for ages! Basically I am concerned that I will learn something and create app's which within a year will be out of date. I am confused why Python developers are advocating that newbies learn an old and presumably soon to be legacy version of the language. I remember when this kinda happened with PHP and versions 4 and 5. I still run across hosts who default to PHP4!? WTF? Its 2012! Is PYthon3 really that new that you shouldn't pick it up or is this developers still refusing to update?
- eevee 14y ago
  Python 2 versus 3 isn't anything like PHP 4 versus 5. The problem is that there are a few minor but backwards-incompatible changes to the syntax in py3. Libraries can't update until all their dependencies update. And web frameworks are some of the most complex software with the most dependencies, so they're updating last. It's still pretty much the same language behaving in the same way, though. If you know Python 2 really well, it'll take all of five minutes to get accustomed to Python 3. Just don't worry about it and learn 2 until people stop telling you otherwise. :)
  - mkopinsky 14y ago
    "Don't worry, migration from Python 2 to 3 is really easy. It'll take 5 minutes to learn." "Migration for libraries from Python 2 to 3 is really hard. It's taken them a few years and counting." ??
    - eevee 14y ago
      Right. Learning Python 3, once you know 2, is really easy. Library maintainers have two problems: they have to twiddle their thumbs until all their dependencies have ported, and then they have to get their code running against both 2 and 3. The former is exactly why I'm saying to use 2 for now, and the latter is easy if you only support 2.7 but rather more difficult for projects that still want to run on some archaic thing like 2.3.
- 14y ago
languagehacker 14y ago
I really don't think it's worth taking this guy seriously. First he writes a worthless and inaccurate lambast of PHP, and now he's trying to "convert" people to Python by telling us Unicode sucks. Get a life.
- damncabbage 14y ago
  > ... by telling us Unicode sucks. Could you tell us where he did this? (I didn't notice it on the first time through; he did say to use Unicode everywhere inside your code, though, and to not do anything rude like converting Unicode to ASCII by stripping non-latin1 characters.)
  - smacktoward 14y ago
    Right under the big bold "Unicode" header. The very next line is > Unicode sucks. This is a universal truth. (In fairness, I think what he's really getting at is that dealing with Unicode in languages that were created before it became ubiquitous sucks, not Unicode itself. But if you start off your discussion of Unicode with the statement that "Unicode sucks", you shouldn't be surprised if people think your beef is with Unicode rather than with the tools we use to deal with it.)
    - damncabbage 14y ago
      Point. Mind you, he follows that with: "(I’m lying. Dealing with encodings sucks. Unicode is great. It’s complicated. I’ll write about it later.)" I think I'll wait for the follow-up article.
- eevee 14y ago
  Who am I trying to convert? The article answers the question asked in the beginning—a question I've been asked several times since writing the PHP article.
Marwy 14y ago
I've seen Flask mentioned here few times. Is Flask better than Bottle?
- lclarkmichalek 14y ago
  In my humble opinion.. Yes. I feel bottle sacrifices just a little too much for the sake of being a single file distribution. The lack of any (mainstream) templating engine might hinder newcomers, and Flask uses one of the best python templating engines around. I also find Flask's documentation to be more extensive and better laid out. Overall I would recommend Flask if you want to write a full featured website, Bottle if you are looking to write some kind of API layer, or similarly bear bones functionality, and will not require many "batteries included".
  - Marwy 14y ago
    You can use Jinja2 with Bottle: > pip install Jinja2 from bottle import jinja2_template as template
gouranga 14y ago
Good article apart from one thing - avoid the hell out of session state. This becomes the dumping ground for all sorts of crap and will slowly knacker your app. You should only persist enough information to identify the user between requests and keep the rest stateless. We do that using encrypted cookies containing the user id, display name and correlation id. I've just spent 6 months entirely removing session state from an asp.net app and the performance gain is amazing.
wink 14y ago
I was thinking this could redeem the author's credibility a little after the PHP rant, but the irrational hatred for Cheetah sounded very familiar. I only used it in one project, a few years ago, but there's really no bad thing about it I couldn't say about any other templating system in any language I ever tried. I wouldn't really take offense with that, but while the XSS chapter still has some points, the Sanitizing chapter goes on to bash PHP for a subjective trend of sanitizing (examples?) just to go on and present an example of sanitizing. In general, it was a decent article, but sadly again much more opinionated than needed. It's one thing to suggest one technology over the other but it doesn't help to make people who actually agree with your point have their eyes rolling every second paragraph. (That the author doesn't like MySQL was to be expected after the PHP rant as it usually goes hand in hand, but showing some real reasons for Postgres over MySQL would have been nice.) Still the same criticisms apply, I'd wager most people use PHP (or MySQL for the matter) because it's MINDBLOWINGLY AMAZING, but because a) the infrastructure is set up (especially DBAs hate to mix and match in my experience) b) the people at hand can use the language and use it well c) it gets the job done. quickly. sometimes "good enough".
- jeltz 14y ago
  Explaining why what he does not like about MySQL would have been moving too far from the subject of the article. And I liked the sanitizing chapter. It explains well why "sanitizing" is a misused word, which should be avoided. Almost always when I see people call it "sanitizing input" they do not seem to know how to handle input correctly.
  - eevee 14y ago
    I don\'t see the problem with \"sanitizing\". It\'s easy: just add a \\ before every quote and the string is totally safe!
- eevee 14y ago
  I'm kinda the de facto owner of Cheetah for a fairly heavy user of it—quite possibly the heaviest. It may appear-to-work for a small project, but you would not believe the insanity that lurks beneath the surface. It's been effectively dead for years, anyway, and the author admitted he'd jumped ship for Mako in 2008.
Jebus 14y ago
The problem with PHP is that people is not used to languages/communities evolving so fast. You should check Symfony 2, then tell me if you need a better structured or more feature complete framework.
tantalor 14y ago
> Some have helpers for creating RESTful routes Can somebody point to an example of this?
jiggy2011 14y ago
Is there any cheap & easy webhosting available for Python? Occasionally I get commisioned to build small websites ( < 50 visitors per day) and for that I want to be able to build the site in a day or two. I don't want the hassle/expense of having to setup and run VPS/AWS infastructure. I just want to give someone a bunch of files and say "sign up for some cheap webhosting, ask them to give you a DB called X and upload these". I usually end up just doing it in PHP, but it has always felt like a poor reason to choose a language with so many warts.
- tantalor 14y ago
  Heroku is a good choice, > This quickstart will get you going with Python and the Flask web framework on the Cedar stack. For Django apps, please see the Django quickstart. https://devcenter.heroku.com/articles/python https://devcenter.heroku.com/articles/python It can be very cheap or free at low scale, > Each application receives 750 free dyno hours per month. https://devcenter.heroku.com/articles/dynos https://devcenter.heroku.com/articles/dynos
  - deleted 14y ago
    [deleted]
  - jiggy2011 14y ago
    Looking at that, it looks quite complicated. Having seperate web/worker dynos, deploying via git etc. I am assuming with this , you would very much build you application around their infrastructure so it would become fairly well coupled to it? A lot of services (such as godaddy) will offer packages like domain name + email + web hosting for a flat monthly fee. This keeps things very simple, but the snag is they only ever seem to support PHP. I don't really want to have to explain to someone why they have a massive bill because some action on their website caused them to use lots of "dyno hours".
  - evilduck 14y ago
    Replying to Jiggy, but can't directly reply since it's dead: No, a simple Rails app is not very coupled to Heroku. The deployment process is simpler and pretty unique to Heroku, but it's usually pretty easy to move away from Heroku or deploy in parallel to another location. I actually deploy one app to Heroku and I have an offsite backup process that deploys the same codebase to a NGINX/Passenger setup and clones the production Heroku data to that instance. Your mileage will vary, of course. If you start using a bunch of Heroku plugins, you'll find it's harder to maintain an easy dual-deploy setup.
pbreit 14y ago
By far the easiest way to get started with Python web development is Web2py which comes as a self-contained install where you can get started in 5 minutes. So you automatically get "request" information, big deal.
- eevee 14y ago
  Flask comes as a self-contained install where you can get started in 5 minutes.
  - yashchandra 14y ago
    But Flask is a micro framework while web2py is a full stack framework. Comparing apples to oranges IMHO.
  - pbreit 14y ago
    Flask doesn't help much with the database.
VBprogrammer 14y ago
The idea is that a transaction starts when a request starts, and it’s automatically rolled back if there’s an exception. This is behavior you want from the start! It’s half (err, ¼) the point of using a database. I mostly agreed with the rest of the article but this strikes me as massive blooper. I can see no reason this would be considered good advise. It's the database equivalent of the GIL, can't figure out what you actually need to lock? Just lock everything! An example of this going wrong in production, I work in the online gaming (gambling) industry. One of our users won a large jackpot, our code started a transaction, contacted the 3rd party to have them release the funds, recorded the win in the transaction journal, updated the customers balance etc. Then the stored procedure which inserted a row into the outgoing email queue had a small error. This caused all of the database work on our end to rollback. For what its worth, this was discovered during a reconciliation with the 3rd party and the customer received his winnings. My point being, this is a horrible way of dealing with database transactions. Only things which are transactional by nature should be carried out within the same transaction. Obviously your code needs to deal with any errors and carry on or report an error as is appropriate.
- mbowcock 14y ago
  The transaction is internal to the database. It's essentially a list of operations to perform, if something goes wrong it provides a list of things to reverse. If the db transaction fails, then there would need to be some code to handle rolling back operations outside of the database. I don't think db transactions were to fault in your situation.
  - VBprogrammer 14y ago
    I'm not sure I really get what you are trying to say. I know what a transaction is, and I know it wasn't the fault of transactions. It was the fault of our poor use of transactions, in the same monolithic transaction pattern that the OP appears to be advocating.
    - zzzeek 14y ago
      transaction-per-request is by far the best default pattern to use. If some particular methods have special needs, like needing to break up the operations into multiple transactions to deal with third-party communication, those are the exceptions. The alternatives to transaction-per-request are autocommit, or explicit transactions required at all times. Autocommit is a terrible choice because now you've lost all atomicity and isolation for dependent operations (locking is also not much of an issue. If you're doing VB, then you're on SQL server, which has some of the worst locking behavior - turn on snapshot isolation to make it bearable). Explicit transactions required at all times is a terrible choice because now your app is littered with what is 90% of the time unnecessary boilerplate.
optymizer 14y ago
Personally, I _like_ PHP because, at the core, it is a collection of utility functions to write webapps quickly. Here's a small set of those function that I would like to see somewhere else (like in Python for example): Save a file: file_put_contents() Load a file: file_get_contents() Trim whitespace: trim() Print a string (even numbers!): print $str Dump an array: print_r() Print the stack trace: print $e->getTraceAsString() Want to embed HTML? Go ahead, _without_ any of this nonsense: print "<table><tbody><tr><td>"+str(val)+"</td></tr></tbody></table>" Want to check for errors and improve the quality of the code? Go ahead! Use lower level functions like fwrite, fread, etc; most functions return FALSE on error, use try/catch, throw Exceptions, create custom Exception classes, go nuts with over-architecting if that's your thing. Also, as someone who knows C and C++ rather well, I find PHP completely intuitive, very easy and flexible, as opposed to: if __main__=="__main__": main() and passing self around is just plain redundant. The icing on the cake is that a huge part of the built-in functions wrap and extend existing C functions: strpos, strlen, so the language rarely gets in your way. The docs are pretty good (there's room for improvement). So you can be a zealot all you want, but the truth is: the language doesn't make your code reliable - YOU make the code reliable and, from my experience, people who bash a language rarely know what they're talking about and it usually just boils down to personal preferences like braces vs no-braces. Lastly, I wish you all the best in your fanatic bashing of a good tool that has proven itself appropriate for web applications. Everyone's tired of the following example, but I'm going to say it anyway: Facebook (and thousands of other large websites). Feel free to be in denial about that.
- egonschiele 14y ago
  In Ruby: # Save a file f.write(str) # Read a file f.read # Trim whitespace " foo ".strip # Print anything puts 1 # even numbers! puts File.open("foo", "w+") # even file handles! puts [1, 2, 3, 4] # even arrays! puts [].class # even classes! puts [].method(:size) # even functions! # Dump an array (see above) Python is similarly clear: # Save a file f.write(str) # Read a file f.read() # Trim whitespace " foo ".strip() # Print anything print 1 # even numbers! print open("foo", "w+") # even file handles! print [1, 2, 3, 4] # even arrays! print [].__class__ # even classes! puts [].remove # even functions! # Dump an array (see above) Ruby and Python are extremely well documented. They have great standard libraries which wrap existing C functions too...and wrap them in a consistent fashion. They are also the second and third most popular language on Github, respectively...which means tons of great libraries to solve almost any problem you can think of. Ruby and Python are just as easy to use as PHP.
salimmadjd 14y ago
Great article! For those of you who say how easy PHP is, it's because you don't remember the early days when you had to compile php to run on your box, only to watch it fail after an hour of compilation :) history aside, these are just tools. For many site, perhaps for majority of tasks, PHP might be the best tool for the job. Once you start doing more complex stuff that will require additional libraries and modules then you need to look into other languages. I used servlets from very early days, just because I could never understand another man's perl code and I thought the architecture was better. However J2EE got so big and academic that took all the fun out of coding. I've recently started to do some stuff in python and the fun is back again. I love all the NLP libs that are available for python in addition to vast support and ease of coding. Not to mention, I like the python community more than ruby (rails really). It just seems like python guys come from a stronger CS background and are not some over-night rail guys who want to push their faith down your throat.
salimmadjd 14y ago
Great article! For those of you who say how easy PHP is, it's because you don't remember the early days when you had to compile php to run on your box, only to watch it fail after an hour of compilation :) history aside, these are just tools. For many site, perhaps for majority of tasks, PHP might be the best tool for the job. Once you start doing more complex stuff that will require additional libraries and modules then you need to look into other languages. I used servlets from very early days, just because I could never understand another man's perl code and I thought the architecture was better. However J2EE got so big and academic that took all the fun out of coding. I've recently started to do some stuff in python and the fun is back again. I love all the NLP libs that are available for python in addition to vast support and ease of coding. Not to mention, I like the python community more than ruby (rails really). It just seems like python guys come from a stronger CS background and are not some over-night rail guys who want to push their faith down your throat.
pimentel 14y ago
Should I really learn Pyramid instead of Django? I'm thinking about what would give me most value as a developer, one who already knows his python.
- grey413 14y ago
  It's a tradeoff. Django is a full-stack framework, which integrates lots of components such as templates, form generation, and an ORM. This means that you can get off the ground quicker, and that the community is all more or less on the same page. The downside is that if you want to do something that Django isn't good at (complicated database stuff, logic in templates, etc), you are in for a world of pain (reportedly). Overall, Django is a great default for making CMS-type sites, but can become a technical debt if your requirements outgrow it. Pyramid, on the other hand, deliberately not a full stack framework, sacrificing ease-of-use for flexibility. It doesn't include any database opinions at all, can swap templating languages on a whim and wouldn't know a form if you hit it over the head with one. The upside is that it has first class core components, really well defined extension points, an unmatched routing system, and a few truly excellent plugins (I love you pyramid_tm). The downside, of course, is that you will own your entire stack, which means that A) there is more up-front work researching, designing, and developing your application's component stack and B) there's no central community guaranteed to be using the same stack as you. Overall, pyramid is suited for essentially any use case, so long as you put the work into it. tldr: Django is (somewhat) inflexible but easy, Pyramid is flexible but more demanding. Both are excellent. There are probably more jobs working with Django, if that's a consideration.
javajosh 14y ago
Google App Engine for Python. You don't have to configure your host, you get great tooling and documentation, and a very good community of users.
jpwagner 14y ago
Great overview.
jipipayo 14y ago
Its funny how Ruby hordes overwhelms this thread talking about ruby not python nor php :-D

230 points by jrheard 14y ago

off-topic: love the greek-lettered ordered list.

gcb 14y ago

Say wat you want of php. But it's (insert personal pejorative option) made for it. Sure Its a_little_inconsistent AndSomewhatChaotic But all the basics for the web are incredible accessible right away. With every other language you have to start with a framework. I find php easier than rails to prototype applications and do fast hacks that need a web face. It's simply the right tool for the job on those occasions. Of course, later they become huge systems...

eevee 14y ago
That's why e.g. Flask exists: it gives you the basics, plus light structure and templating and routing and XSS protection and deployment options and whatever else. With no setup and no boilerplate. It's about as much effort as typing `<?php`.
- chrisguitarguy 14y ago
  While that's true (and I do love Flask), PHP comes installed on every discount web host. Deploying a PHP app is as easy as using FTP, deploying a Python app can be -- but doesn't have to be -- complex. I'd say this is the bigger sticking point than the framework. Obviously Heroku and other PAAS providers are changing the game as far as deployment ease. It should be to see what happens in the next few years on that front.
  - espeed 14y ago
    Deploying a PHP app is as easy as using FTP, deploying a Python app can be -- but doesn't have to be -- complex. Easy != Simple && Easy != Good See "Simple Made Easy" (http://www.infoq.com/presentations/Simple-Made-Easy http://www.infoq.com/presentations/Simple-Made-Easy).
  - eevee 14y ago
    It's a chicken-and-egg problem. Best I can do is encourage more people to write more Python software, so those crappy free hosts are more inclined to support running it. Until then, I don't think it's terribly unreasonable to pay twenty bucks a month for a server to play with. That's less than AT&T wants to charge me for sending a thousand 160-byte messages.
    - joering2 14y ago
      "crappy free hosts" ?
    - espeed 14y ago
      Don't mess with "crappy free hosts" -- just run it on a free Heroku dyno (http://www.heroku.com/pricing http://www.heroku.com/pricing). Kenneth (http://kennethreitz.com http://kennethreitz.com) shows you can get good performance with Flask on the free dyno (http://flask.pocoo.org/mailinglist/archive/2012/2/22/flask-on-heroku-%2B-gunicorn-static-files/#cff05916ae6854557b93d0226cb87151 http://flask.pocoo.org/mailinglist/archive/2012/2/22/flask-o...).
      - eli 14y ago
        That's a fair bit more involved than "FTP files to my web host and they usually just work"
        espeed 14y ago
        It's actually easier... $ git push heroku master
        eli 14y ago
        Sure, well I would hope it's easy to do a one line deploy to any platform and with any language... once you set it up. You left out freezing requirements for pip, setting up cedar, etc. Nothing like that for a simple PHP app. I don't want to overstate the case; deploying Flask isn't hard, but deploying PHP is stupidly easy.
BrandonM 14y ago
That's a nice sentiment that's completely inaccurate. Even 6 years ago when I first started programming Python, simple Python cgi scripts were very easy to write. It's as simple as: print """\ Content-type: text/html <html>...</html>""" With %(var)s interpolation, you can even slap in locals() easily to trivially put variables' values into the page.
- eli 14y ago
  That doesn't seem like it will scale very well at all. Or am I missing something?
  - justincormack 14y ago
    PHP doesn't scale well either. You can rewrite for scaling later.
- gcb 14y ago
  and you think that manually handling headers is more straightforward than php? I disagree.
  - BrandonM 14y ago
    "Manually handling headers"? That is how people wrote websites in the early 2000s. Many cgi scripts were cobbled together in Perl. I found that I liked Python better. I understand that in PHP you just add some <?php ...> stuff to an otherwise normal HTML file, but the situation in Python, with its multiline strings that support variable interpolation, isn't much worse. Just add the lines I mentioned to the top (treat is as a recipe if you like), and the rest is better than PHP.

akkartik 14y ago

What's wrong with mysql?

cbg0 14y ago
Apparently, it isn't PostgreSQL; If you have no need for Postgres features and you're not familiar with it, sticking to MySQL is fine.
- gbog 14y ago
  Well you can say the same for windows vs Linux or visual basic vs any other language, and you can also continue using paper glue to attach paintings on the wall. It is not a matter of what you need, it is a matter of using good tools that will help you do good work, understand better what you do, build durable products, and so on. Just one example: MySQL will not complain if you add a check constraint but will not actually add it to your schema. That's a very Microsoft-y way to handle things, and should give cold sweat to any coder.
  - cbg0 14y ago
    This is actually documented behavior: "The CHECK clause is parsed but ignored by all storage engines." From: http://dev.mysql.com/doc/refman/5.5/en/create-table.html http://dev.mysql.com/doc/refman/5.5/en/create-table.html I believe it was left to support certain migrations(?). You can create a trigger instead. I'm pretty certain many people will consider MySQL a good tool with which they produce good work. While it may have its quirks, it's present on virtually all shared hosting environments, just like PHP, so it's very easy to create and deploy an application powered by both these technologies.
    - gbog 14y ago
      So, you are telling me that it is a good thing, a normal behavior for a reliable tool to just ignore instructions I send to it and do nothing with it, not even a warning? So when I migrate a database, I have to carefully check each and every instructions (schema and data) and make sure MySQL did not "decide" it was not worth it and just silently threw it by the window? I have hard time to believe you are serious here...

ashray 14y ago

This guy failed to cover web.py which is one of the fastest ways to start prototyping a web app in python. =/ http://webpy.org/ http://webpy.org/ I personally use it for a small app which returns (and stores) search suggestions from redis.

gbog 14y ago

"MySQL is the PHP of databases". Strange, I just had this sentence popping in my head yesterday. I'm seriously considering writing a list of its wrong doings. Great article overall.

jrheard 14y ago
I'd be interested in reading that list!
AgentConundrum 14y ago
Please write that list. I'd be very interested in reading it.
glogla 14y ago
Color me as another interested specimen.
- gbog 14y ago
  I wanted to do that now but did some lego with my kid instead, will keep you 3 informed when done.
  - gbog 14y ago
    It seems an article on Ars Technica has already compiled some defect of MySQL: http://arstechnica.com/civis/viewtopic.php?f=20&t=92525 http://arstechnica.com/civis/viewtopic.php?f=20&t=92525 Another thing that reminds of PHP, the list of commands: mysql mysql_client_test_embedded mysql_find_rows mysqlrepair mysql_tzinfo_to_sql mysqlaccess mysql_config mysql_fix_extensions mysqlreport mysql_upgrade mysqladmin mysql_convert_table_format mysql_fix_privilege_tables mysql_secure_installation mysql_waitpid mysqlanalyze mysqld mysqlhotcopy mysql_setpermission mysql_zap mysqlbinlog mysqld_multi mysqlimport mysqlshow mysqlbug mysqld_safe mysql_install_db mysqlslap mysqlcheck mysqldump mysqlmanager mysqltest mysql_client_test mysqldumpslow mysqloptimize mysqltest_embedded Why the hell show we want a 'mysqldumpslow'? Is it because mysqldump is fast but wrong? And why not mysql_dump? I have started with MySQL for my first (php) website, and to me the database was just the natural storage, I had no idea of the problems, because I didn't know that a relational database is a particular well-defined mathematical object, which asserts truths about the "world" in a manner that makes it possible to model this world safely and ask questions about it. Then I used PostgreSQL at my previous work, and discovered it all, the hard way. And PostgreSQL has (almost) always been a reliable companion taking care of the most valuable asset: the Data. Then I switched job and have to use MySQL again. I live with it, it's fine, but the difference is not benign, and I sometime wonder if the NoSQL movement is not a partly a misunderstanding and should renamed NoMySQL: when using an unreliable datastore, it is certainly better to use one that is explicitly not reliable and do not force on you the relational model while, at the same time, not giving you its strengths.

Xuzz 14y ago

I'd say the necessity of this post is why PHP is as popular as it is. With PHP, there are no package managers I have to install; there is no template language to learn; there is often no version control; there is no "framework"; etc. You just drop in a .php file and, most likely, it will just run. If I need a quick dynamic page on my server, it's much easier to do this in PHP than in Python or Ruby. Until Python or Ruby have that kind of simplicity, they can't overtake PHP. While it might not be the kind of design that leads to well-designed web apps or even good code, it is the kind of design that leads to more — especially less technical, or, like me, lazy — users. It's up to the developers of those languages if this is even a market they want. There may need to be something new to do the same job as PHP, but better, without the innumerable warts.

eevee 14y ago
Most of the post _isn't_ strictly necessary. You don't need a database to get your feet wet. You don't need to care about XSS for your first throwaway app (though, arguably, you should). I pimp Mako precisely because there's no separate language to learn: the core syntax is just Python. I tried to describe the _ecosystem_, and I assume any serious PHP application will care about most of the same things. Here's all you really need: look at http://flask.pocoo.org/ http://flask.pocoo.org/ and do that thing it says right there. You don't even need to install a separate web server. (Yeah, yeah, 5.4, I know.) A "quick dynamic page" is a deployment problem. If you're already running Apache and mod_php, you already have an environment ready to go to serve PHP, so of course it'll be easy for you. I don't run Apache, so PHP doesn't really help me there. (mod_passenger promises to, but I haven't tried it with Python yet.)
- lloeki 14y ago
  Also, http://pow.cx/ http://pow.cx/ (Ruby I know, but it shows such things can be done.) Also the argument of python/ruby requiring lots of configuration while php would not is just plain bullshit. Making PHP run with Apache (esp. on a windows machine) without stuff like EasyPHP (and this is where you stop comparing apples to oragnes) is by and large tough on the beginner.

capkutay 14y ago

I like java for web app development, simply because it has a well-structured api and a massive community of developers who have run in to the majority of the road blocks you will most likely encounter on the way to launching your app.

yolesaber 14y ago
What frameworks and platforms would you recommend for web development with java? I am writing my senior project at college in java (mainly because of the wide amount of image processing libraries available) and would love to add web capabilities.
- AlexSerov 14y ago
  http://www.hybridserverpages.com/ http://www.hybridserverpages.com/ Just two days learning curve.
- cletus 14y ago
  I tend to prefer Python/Flask for Web dev to Python but if you are inclined to use Java there's only really one framework that doesn't make me want to tear my eyeballs out. That framework is Spring MVC. It is DI, adapters for vendor-specific libraries and utility. It's probably not the easiest thing to start with just because it is so flexible that it can be hard to know where to start. A good "Hello World" Spring MVC 3.1 app would go a long way. I really would like to use the Play Framework and it's so close to being great but it just falls too far short. I really liked Play 1.x with Groovy templates. It was simple and it pretty much just worked. Play 2.x has gone in a radically different (and backwards incompatible) direction. It is now part of Typesafe and the goal of Play 2.x is to make Scala a first-class citizen. The problem is that many of the niceties of Play are either harder to use or just outright missing in Java Play 2.x (eg AppEngine support and the OAuth client were all present in 1.x and are slated for a future 2.1 release). There really is a niche for a Java Web framework that like Play ditches the JEE/servlet model in favour of the Rails/Django way of doing things (including dynamic class reloading) but doesn't do it in a way that makes me want to stab myself repeatedly. This would include playing nice with the Java ecosystem (seriously just use Maven and to hell with SBT).

zobzu 14y ago

"I only know PHP" "I just trashed PHP rather harshly" "I want to learn python" Well, you're doing it wrong. How can you trash PHP if you know no other languages ?! You're following articles, posts saying PHP is bad and.. you decide then that's right it's bad! Ever though about thinking on your own first? Like, actually trying a language (python, why not) then deciding if it's better? This kind of stuff always amaze me. You know, sheepish.

eevee 14y ago
This is part of an FAQ series. The bolded part ("I only know PHP...") is the question I'm answering. I'll leave you to contemplate the irony here.

yaix 14y ago

Nice littel overview, but... "Unicode sucks. This is a universal truth." And here I stopped reading. Unicode is the best thing around, what sucks it that Py2 does not implement it very well. Py3 does, and that is the main reason I really would like to use it and hope Django will soon fully support it. (Because: there are other languages beside the European ones)

eevee 14y ago
Fair point. Correction: working with encodings sucks. Py3 isn't magnitudes better with Unicode; it's better about converting incoming bytes, and it makes literals into real strings. But the former isn't necessarily a good thing, and you can get the latter with a `__future__` import. Always dying on implicit conversions is definitely nice, though.
- adeelk 14y ago
  Working with encodings is indeed annoying in Python, but it’s not a “universal” problem.
  - anuraj 14y ago
    There is a language called 'Java' where every string is in unicode, and I do not remember ever running into an issue!
    - duskwuff 14y ago
      Except that Java strings aren't in Unicode. They're in UTF-16, which is the worst-of-all-worlds encoding. (It's big and heavy, and it still has multibyte sequences. They're just rare enough that you're likely to forget about them during testing.)
      - 0x09 14y ago
        UTF-16 is most certainly Unicode, even if it isn't the preferred flavor.

joeycfan 14y ago

Learn Python. It's easy. It's like Internet Fortran.

exim 14y ago

In python, stay away from default arguments for methods/functions. EDIT: yes, mutable default values: http://effbot.org/zone/default-values.htm http://effbot.org/zone/default-values.htm

espeed 14y ago
Do you mean don't use defaults that contain mutable values?

achristoffersen 14y ago

I have no idea why web2py gotten such a bad rep. I am a beginning webdeveloper and seriously: web2py is a pleasure to work with. Simple to start, deploy, port and hack. It's backwards compatible and has a template language that really is non existant as so far as its pure python. Compare that to Rails - which is (comparable) hell to set-up and breaks with upgrades etc. If you want python web development to be simple, web2py is the way to go. Since I don't have a CS degree and I have often been wrong before - there might be a real problem somewhere. But I don't think so. One of the reasons for this is that Jakob Moss removed his web2py bashing from this thread. Didn't edit - removed it: https://www.quora.com/Is-web2py-a-good-Python-web-framework/answer/Anthony-Bastardi https://www.quora.com/Is-web2py-a-good-Python-web-framework/...

irahul 14y ago
> But I don't think so. One of the reasons for this is that Jakob Moss removed his web2py bashing from this thread. Didn't edit - removed it: https://www.quora.com/Is-web2py-a-good-Python-web-framework/.. https://www.quora.com/Is-web2py-a-good-Python-web-framework/.... What did he remove? https://www.quora.com/Is-web2py-a-good-Python-web-framework/answer/Jacob-Kaplan-Moss-1 https://www.quora.com/Is-web2py-a-good-Python-web-framework/... This isn't the first instance of Django/Flask people not agreeing with web2py design and implementation, and they have been vocal about it a couple of times. http://www.reddit.com/r/Python/comments/ex54j/seeking_clarification_on_pylonsturbogearspyramid/ http://www.reddit.com/r/Python/comments/ex54j/seeking_clarif... Look for comments by mitsuhiko(flask dev) and jacobian(django dev).
- achristoffersen 14y ago
  Sorry - I remembered that I on an earlier occasion couldn't find JKM' answer. It's there now - and I personally don't find it convincing. Again - I am a novice and has no authority here. – I'd edit above if I could. I am sorry that I wrote wrong info. Thanks for the reddit link. As you say it seems to me most of the flak is from not agreeing on something. But can an oppinion be correct? And yes: Mitsuhiko seems to be a super cool, clever and friendly guy. In my last project I played around with request. Lovely it was. Anyways: my point was not to express that web2py is the greatest thing invented since bacon. Only that I don't understand why the python community dislike it so. After all - web2py makes it very easy to build stuff. Hence it will probably attract people to the language. Hence make it more feasible for webhosts to offer python friendly environments. And that should be a good thing? Especially in the context of OP - "how do PHP guy start with python"?

bobsy 14y ago

I would love to switch to Python from PHP but I can't. The reason is I keep getting told to learn Python 2. Python 3 has been out for ages! Basically I am concerned that I will learn something and create app's which within a year will be out of date. I am confused why Python developers are advocating that newbies learn an old and presumably soon to be legacy version of the language. I remember when this kinda happened with PHP and versions 4 and 5. I still run across hosts who default to PHP4!? WTF? Its 2012! Is PYthon3 really that new that you shouldn't pick it up or is this developers still refusing to update?

eevee 14y ago
Python 2 versus 3 isn't anything like PHP 4 versus 5. The problem is that there are a few minor but backwards-incompatible changes to the syntax in py3. Libraries can't update until all their dependencies update. And web frameworks are some of the most complex software with the most dependencies, so they're updating last. It's still pretty much the same language behaving in the same way, though. If you know Python 2 really well, it'll take all of five minutes to get accustomed to Python 3. Just don't worry about it and learn 2 until people stop telling you otherwise. :)
- mkopinsky 14y ago
  "Don't worry, migration from Python 2 to 3 is really easy. It'll take 5 minutes to learn." "Migration for libraries from Python 2 to 3 is really hard. It's taken them a few years and counting." ??
  - eevee 14y ago
    Right. Learning Python 3, once you know 2, is really easy. Library maintainers have two problems: they have to twiddle their thumbs until all their dependencies have ported, and then they have to get their code running against both 2 and 3. The former is exactly why I'm saying to use 2 for now, and the latter is easy if you only support 2.7 but rather more difficult for projects that still want to run on some archaic thing like 2.3.
14y ago

languagehacker 14y ago

I really don't think it's worth taking this guy seriously. First he writes a worthless and inaccurate lambast of PHP, and now he's trying to "convert" people to Python by telling us Unicode sucks. Get a life.

damncabbage 14y ago
> ... by telling us Unicode sucks. Could you tell us where he did this? (I didn't notice it on the first time through; he did say to use Unicode everywhere inside your code, though, and to not do anything rude like converting Unicode to ASCII by stripping non-latin1 characters.)
- smacktoward 14y ago
  Right under the big bold "Unicode" header. The very next line is > Unicode sucks. This is a universal truth. (In fairness, I think what he's really getting at is that dealing with Unicode in languages that were created before it became ubiquitous sucks, not Unicode itself. But if you start off your discussion of Unicode with the statement that "Unicode sucks", you shouldn't be surprised if people think your beef is with Unicode rather than with the tools we use to deal with it.)
  - damncabbage 14y ago
    Point. Mind you, he follows that with: "(I’m lying. Dealing with encodings sucks. Unicode is great. It’s complicated. I’ll write about it later.)" I think I'll wait for the follow-up article.
eevee 14y ago
Who am I trying to convert? The article answers the question asked in the beginning—a question I've been asked several times since writing the PHP article.

Marwy 14y ago

I've seen Flask mentioned here few times. Is Flask better than Bottle?

lclarkmichalek 14y ago
In my humble opinion.. Yes. I feel bottle sacrifices just a little too much for the sake of being a single file distribution. The lack of any (mainstream) templating engine might hinder newcomers, and Flask uses one of the best python templating engines around. I also find Flask's documentation to be more extensive and better laid out. Overall I would recommend Flask if you want to write a full featured website, Bottle if you are looking to write some kind of API layer, or similarly bear bones functionality, and will not require many "batteries included".
- Marwy 14y ago
  You can use Jinja2 with Bottle: > pip install Jinja2 from bottle import jinja2_template as template

gouranga 14y ago

Good article apart from one thing - avoid the hell out of session state. This becomes the dumping ground for all sorts of crap and will slowly knacker your app. You should only persist enough information to identify the user between requests and keep the rest stateless. We do that using encrypted cookies containing the user id, display name and correlation id. I've just spent 6 months entirely removing session state from an asp.net app and the performance gain is amazing.

wink 14y ago

I was thinking this could redeem the author's credibility a little after the PHP rant, but the irrational hatred for Cheetah sounded very familiar. I only used it in one project, a few years ago, but there's really no bad thing about it I couldn't say about any other templating system in any language I ever tried. I wouldn't really take offense with that, but while the XSS chapter still has some points, the Sanitizing chapter goes on to bash PHP for a subjective trend of sanitizing (examples?) just to go on and present an example of sanitizing. In general, it was a decent article, but sadly again much more opinionated than needed. It's one thing to suggest one technology over the other but it doesn't help to make people who actually agree with your point have their eyes rolling every second paragraph. (That the author doesn't like MySQL was to be expected after the PHP rant as it usually goes hand in hand, but showing some real reasons for Postgres over MySQL would have been nice.) Still the same criticisms apply, I'd wager most people use PHP (or MySQL for the matter) because it's MINDBLOWINGLY AMAZING, but because a) the infrastructure is set up (especially DBAs hate to mix and match in my experience) b) the people at hand can use the language and use it well c) it gets the job done. quickly. sometimes "good enough".

jeltz 14y ago
Explaining why what he does not like about MySQL would have been moving too far from the subject of the article. And I liked the sanitizing chapter. It explains well why "sanitizing" is a misused word, which should be avoided. Almost always when I see people call it "sanitizing input" they do not seem to know how to handle input correctly.
- eevee 14y ago
  I don\'t see the problem with \"sanitizing\". It\'s easy: just add a \\ before every quote and the string is totally safe!
eevee 14y ago
I'm kinda the de facto owner of Cheetah for a fairly heavy user of it—quite possibly the heaviest. It may appear-to-work for a small project, but you would not believe the insanity that lurks beneath the surface. It's been effectively dead for years, anyway, and the author admitted he'd jumped ship for Mako in 2008.

Jebus 14y ago

The problem with PHP is that people is not used to languages/communities evolving so fast. You should check Symfony 2, then tell me if you need a better structured or more feature complete framework.

tantalor 14y ago

> Some have helpers for creating RESTful routes Can somebody point to an example of this?

jiggy2011 14y ago

Is there any cheap & easy webhosting available for Python? Occasionally I get commisioned to build small websites ( < 50 visitors per day) and for that I want to be able to build the site in a day or two. I don't want the hassle/expense of having to setup and run VPS/AWS infastructure. I just want to give someone a bunch of files and say "sign up for some cheap webhosting, ask them to give you a DB called X and upload these". I usually end up just doing it in PHP, but it has always felt like a poor reason to choose a language with so many warts.

tantalor 14y ago
Heroku is a good choice, > This quickstart will get you going with Python and the Flask web framework on the Cedar stack. For Django apps, please see the Django quickstart. https://devcenter.heroku.com/articles/python https://devcenter.heroku.com/articles/python It can be very cheap or free at low scale, > Each application receives 750 free dyno hours per month. https://devcenter.heroku.com/articles/dynos https://devcenter.heroku.com/articles/dynos
- deleted 14y ago
  [deleted]
- jiggy2011 14y ago
  Looking at that, it looks quite complicated. Having seperate web/worker dynos, deploying via git etc. I am assuming with this , you would very much build you application around their infrastructure so it would become fairly well coupled to it? A lot of services (such as godaddy) will offer packages like domain name + email + web hosting for a flat monthly fee. This keeps things very simple, but the snag is they only ever seem to support PHP. I don't really want to have to explain to someone why they have a massive bill because some action on their website caused them to use lots of "dyno hours".
- evilduck 14y ago
  Replying to Jiggy, but can't directly reply since it's dead: No, a simple Rails app is not very coupled to Heroku. The deployment process is simpler and pretty unique to Heroku, but it's usually pretty easy to move away from Heroku or deploy in parallel to another location. I actually deploy one app to Heroku and I have an offsite backup process that deploys the same codebase to a NGINX/Passenger setup and clones the production Heroku data to that instance. Your mileage will vary, of course. If you start using a bunch of Heroku plugins, you'll find it's harder to maintain an easy dual-deploy setup.

pbreit 14y ago

By far the easiest way to get started with Python web development is Web2py which comes as a self-contained install where you can get started in 5 minutes. So you automatically get "request" information, big deal.

eevee 14y ago
Flask comes as a self-contained install where you can get started in 5 minutes.
- yashchandra 14y ago
  But Flask is a micro framework while web2py is a full stack framework. Comparing apples to oranges IMHO.
- pbreit 14y ago
  Flask doesn't help much with the database.

VBprogrammer 14y ago

The idea is that a transaction starts when a request starts, and it’s automatically rolled back if there’s an exception. This is behavior you want from the start! It’s half (err, ¼) the point of using a database. I mostly agreed with the rest of the article but this strikes me as massive blooper. I can see no reason this would be considered good advise. It's the database equivalent of the GIL, can't figure out what you actually need to lock? Just lock everything! An example of this going wrong in production, I work in the online gaming (gambling) industry. One of our users won a large jackpot, our code started a transaction, contacted the 3rd party to have them release the funds, recorded the win in the transaction journal, updated the customers balance etc. Then the stored procedure which inserted a row into the outgoing email queue had a small error. This caused all of the database work on our end to rollback. For what its worth, this was discovered during a reconciliation with the 3rd party and the customer received his winnings. My point being, this is a horrible way of dealing with database transactions. Only things which are transactional by nature should be carried out within the same transaction. Obviously your code needs to deal with any errors and carry on or report an error as is appropriate.

mbowcock 14y ago
The transaction is internal to the database. It's essentially a list of operations to perform, if something goes wrong it provides a list of things to reverse. If the db transaction fails, then there would need to be some code to handle rolling back operations outside of the database. I don't think db transactions were to fault in your situation.
- VBprogrammer 14y ago
  I'm not sure I really get what you are trying to say. I know what a transaction is, and I know it wasn't the fault of transactions. It was the fault of our poor use of transactions, in the same monolithic transaction pattern that the OP appears to be advocating.
  - zzzeek 14y ago
    transaction-per-request is by far the best default pattern to use. If some particular methods have special needs, like needing to break up the operations into multiple transactions to deal with third-party communication, those are the exceptions. The alternatives to transaction-per-request are autocommit, or explicit transactions required at all times. Autocommit is a terrible choice because now you've lost all atomicity and isolation for dependent operations (locking is also not much of an issue. If you're doing VB, then you're on SQL server, which has some of the worst locking behavior - turn on snapshot isolation to make it bearable). Explicit transactions required at all times is a terrible choice because now your app is littered with what is 90% of the time unnecessary boilerplate.

optymizer 14y ago

Personally, I _like_ PHP because, at the core, it is a collection of utility functions to write webapps quickly. Here's a small set of those function that I would like to see somewhere else (like in Python for example): Save a file: file_put_contents() Load a file: file_get_contents() Trim whitespace: trim() Print a string (even numbers!): print $str Dump an array: print_r() Print the stack trace: print $e->getTraceAsString() Want to embed HTML? Go ahead, _without_ any of this nonsense: print "<table><tbody><tr><td>"+str(val)+"</td></tr></tbody></table>" Want to check for errors and improve the quality of the code? Go ahead! Use lower level functions like fwrite, fread, etc; most functions return FALSE on error, use try/catch, throw Exceptions, create custom Exception classes, go nuts with over-architecting if that's your thing. Also, as someone who knows C and C++ rather well, I find PHP completely intuitive, very easy and flexible, as opposed to: if __main__=="__main__": main() and passing self around is just plain redundant. The icing on the cake is that a huge part of the built-in functions wrap and extend existing C functions: strpos, strlen, so the language rarely gets in your way. The docs are pretty good (there's room for improvement). So you can be a zealot all you want, but the truth is: the language doesn't make your code reliable - YOU make the code reliable and, from my experience, people who bash a language rarely know what they're talking about and it usually just boils down to personal preferences like braces vs no-braces. Lastly, I wish you all the best in your fanatic bashing of a good tool that has proven itself appropriate for web applications. Everyone's tired of the following example, but I'm going to say it anyway: Facebook (and thousands of other large websites). Feel free to be in denial about that.

egonschiele 14y ago
In Ruby: # Save a file f.write(str) # Read a file f.read # Trim whitespace " foo ".strip # Print anything puts 1 # even numbers! puts File.open("foo", "w+") # even file handles! puts [1, 2, 3, 4] # even arrays! puts [].class # even classes! puts [].method(:size) # even functions! # Dump an array (see above) Python is similarly clear: # Save a file f.write(str) # Read a file f.read() # Trim whitespace " foo ".strip() # Print anything print 1 # even numbers! print open("foo", "w+") # even file handles! print [1, 2, 3, 4] # even arrays! print [].__class__ # even classes! puts [].remove # even functions! # Dump an array (see above) Ruby and Python are extremely well documented. They have great standard libraries which wrap existing C functions too...and wrap them in a consistent fashion. They are also the second and third most popular language on Github, respectively...which means tons of great libraries to solve almost any problem you can think of. Ruby and Python are just as easy to use as PHP.

salimmadjd 14y ago

Great article! For those of you who say how easy PHP is, it's because you don't remember the early days when you had to compile php to run on your box, only to watch it fail after an hour of compilation :) history aside, these are just tools. For many site, perhaps for majority of tasks, PHP might be the best tool for the job. Once you start doing more complex stuff that will require additional libraries and modules then you need to look into other languages. I used servlets from very early days, just because I could never understand another man's perl code and I thought the architecture was better. However J2EE got so big and academic that took all the fun out of coding. I've recently started to do some stuff in python and the fun is back again. I love all the NLP libs that are available for python in addition to vast support and ease of coding. Not to mention, I like the python community more than ruby (rails really). It just seems like python guys come from a stronger CS background and are not some over-night rail guys who want to push their faith down your throat.

salimmadjd 14y ago

pimentel 14y ago

Should I really learn Pyramid instead of Django? I'm thinking about what would give me most value as a developer, one who already knows his python.

grey413 14y ago
It's a tradeoff. Django is a full-stack framework, which integrates lots of components such as templates, form generation, and an ORM. This means that you can get off the ground quicker, and that the community is all more or less on the same page. The downside is that if you want to do something that Django isn't good at (complicated database stuff, logic in templates, etc), you are in for a world of pain (reportedly). Overall, Django is a great default for making CMS-type sites, but can become a technical debt if your requirements outgrow it. Pyramid, on the other hand, deliberately not a full stack framework, sacrificing ease-of-use for flexibility. It doesn't include any database opinions at all, can swap templating languages on a whim and wouldn't know a form if you hit it over the head with one. The upside is that it has first class core components, really well defined extension points, an unmatched routing system, and a few truly excellent plugins (I love you pyramid_tm). The downside, of course, is that you will own your entire stack, which means that A) there is more up-front work researching, designing, and developing your application's component stack and B) there's no central community guaranteed to be using the same stack as you. Overall, pyramid is suited for essentially any use case, so long as you put the work into it. tldr: Django is (somewhat) inflexible but easy, Pyramid is flexible but more demanding. Both are excellent. There are probably more jobs working with Django, if that's a consideration.

javajosh 14y ago

Google App Engine for Python. You don't have to configure your host, you get great tooling and documentation, and a very good community of users.

jpwagner 14y ago

Great overview.

jipipayo 14y ago

Its funny how Ruby hordes overwhelms this thread talking about ruby not python nor php :-D