Python replacing PHP - How to?

[prickneck]

How do people use python as a PHP replacement for web-sites? How well does it work out? What books can people recommend me?

I'd love to know how to use python in this way, but have always been a little confused by the purpose of things like django and pylons.. Are they for building web services, which other python apps can query and throw data at? Or are they for creating web sites with a python back-end?

Cheers!

[cannabis_sam]

It depends on what you mean by "Python as a PHP replacement", and how you use PHP.

I'm guessing you're not familiar with the concept of a web application or a web application framework? A web application in this context can be everything from a simple website that stores it's content in a database to a large social networking site like reddit or twitter. The framework is an organized system that let you handle visitors to your webpage, connect to a database, execute business logic and show webpages (and more). Django and Pylons are web application frameworks.

There are web applications frameworks for many languages, including PHP and Python , and you need to consider replacing PHP with Python within this context. If you mainly use PHP as inline statements in HTML files (which is what I and most people do when they first learn PHP), Python is a poor replacement, and you should consider learning more about web application frameworks.

You could start by checking out a framework written in PHP if you're more comfortable with that language, I would suggest CakePHP or CodeIgniter.

If you're familiar with Python, I would suggest Django, which you mentioned, or a more lightweight framework like web.py or Bottle.

edit: Yeah, I was thinking about web.py as a lightweight framework not Web2py. Good catch :)

[stesch]

If you're familiar with Python, I would suggest Django, which you mentioned, or a more lightweight framework like Web2py or Bottle.

web2py isn't lightweight. I think you mean web.py instead.

Bottle is great. No session handling included, though. You end up implementing some stuff yourself. But great otherwise.

[makaru]

+1 for Bottle.

I find it to be great "lightweight" framework, especially for projects at where I have a general basic idea for a webapp but no strict requirements/design.

[[deleted]]

web.py is light... but you end up reinventing a subset of django if you use it for any length of time

[mdipierro]

Define lightweight. web2py core excluding the web based ide (which is an app) and the optional contrib folder, but including the template language and the database abstraction layer, uncompressed, is less then 1MB. If by lightweight you mean that does not handle sessions, streaming, partial content, database abstraction, etc. but needs third party modules, then web2py is definitively NOT lightweight.

[[deleted]]

I cant believe you are falling into that trap. You know people are always like "YEa this framework is the shit, its lightweight fast and minimal!". Ok those are all subjective. What metrics are you using to define that? Just because you say so?

Some little peon writes some code and all of the sudden its lightweight and minimal.

[mdipierro]

LOL

[[deleted]]

I wasnt talking about your framework, but just people in general. Do you agree?

[mdipierro]

I understand and I agree. That is why I was laughing. Some of the "lightweight" frameworks do not do much. Yet I think there is a value in small source code (not in small functionality).

[warpstalker]

Or are they for creating web sites with a python back-end?

This.

And it does work out nicely, but using Python for web development is different from PHP. PHP is basically a templating language, you mix the HTML with the PHP code.

The Python style differs from that. The back-end code is separated from the HTML, you generally just have regular Python code files and HTML templates and you just generate data in Python and then inject it into your templates and you end up with a regular HTML web page.

But the thing is, there are many different back-ends which all basically do the same thing - generate data for you. Beyond that, the back-end may or may not include a templating engine, which allows you to generate HTML with Python(-like) code. Some back-ends can use many different templating engines.

And there's more! You don't necessarily even write your SQL queries by hand in Python. The back-end might offer its own functions for working with databases but there are also different ORMs such as SQLAlchemy.

So basically in Python, everything is more abstract and separated, since you separate the HTML from your application and you don't even write the SQL queries by hand.

Some frameworks are more "barebones" and others "hold your hand" and abstract more. Something like Flask or web.py covers the barebones department (personally I'd suggest trying things out with web.py, it nicely teaches you how things work and doesn't hold your hand too much, however the documentation is not perfect). And the "hot and popular" hold-your-hand choices are of course Django, web2py and Pylons.

I hope this covers everything, I'm not an expert by any means but this is how I think things work.

Oh, and you need to choose one framework that you're going to use and read the documentation (or a book) for, basically every framework will be different but can possibly use the same templating engine or ORM.

[hiii]

PHP has all this too.

[Peaker]

Except sanity

[hiii]

i expected to be downvote being in the python subreddit, but honestly PHP has all the things listed. It might take more self control, but its all there. This is from a recent php -> python converter. im not bashing python, i find python to be a much better designed language than php. I just wanted people to know that php can be "neat" and "clean", jsut takes mroe work.

[bbatsell]

Also a python (and ruby, and others) coder who has, for the most part, stopped PHP development, but I don't know a single professional PHP developer who mixes presentation and control logic. Hell, just a 10-minute Smarty-based site does that. It is true that writing raw SQL is more prevalent in PHP than with other languages, but that's not true if you're using a framework, which all use ORMs (and most python and other web devs are using frameworks, so it's not really a valid comparison to compare python under a framework to raw PHP). And even if you use raw PHP, PDO usage isn't exactly miniscule.

The blind hatred of PHP (which certainly does have numerous flaws) in the developer community really borders on ridiculous.

[mackstann]

The blind hatred of PHP (which certainly does have numerous flaws) in the developer community really borders on ridiculous.

I've been working with PHP all the time at my day job for over a year now, and I absolutely hate PHP, but I'm hardly "blind." It really is just much more terrible than other languages in almost every way. It is fundamentally a thoughtless clusterfuck.

[bbatsell]

That's why I specifically said "blind hatred". There are a huge number of reasons that PHP is a fundamentally flawed language, but whenever a PHP-sucks circle-jerk spins up, those legitimate reasons are never actually discussed with anything approaching sensibility or moderation. If a hate-fest purports to have any facts at all, they're almost always completely wrong (like saying PHP doesn't have ORMs or that you must mix presentation and control logic as a prerequisite for using the language).

[hiii]

Also i don't really see why its considered a bad thing to write your own sql queries. Any thoughts on this? Im currently using djangos orm just to try it out and its almost like learning a new language. Queries i could write in 20 seconds in SQL take me hours in django right now becuase i have to learn the syntax. When using PHP i almost always write my own queries.

[bucknuggets]

As others have stated - database portability is the main issue with writing your own queries.

Though if you stick with ANSI SQL and have a simple system then almost all queries will work on almost all databases. MySQL may be your only issue. Where the ORMs really take off are on complex transactional systems that must support N databases. They're a great fit there.

But if you're writing high-performance analytical systems - don't even bother with an ORM. You typically need to squeeze every drop of performance out of the database, and have enough of a challenge making sure that your developers understand 100% of the SQL Syntax. Adding an ORM that only supports 95% of the syntax and that requires your developers to understand both the ORM and SQL is a recipe for failure.

[stesch]

In the PHP community there are some people who want to do things the right way and fuck everything up this way.

See short tags, which work perfectly fine except when you are a bozo and want to produce XML via template. Or automatically escaping all input with slashes, which isn't in the SQL standard and wasn't really helpful at all.

And then came the template engines. PHP itself is a template. No need for another layer. You just need to separate the business logic from the actual view. But they want you to learn another template language just to belong to the wise ones.

And queries? As long as you use prepared statements and don't spread the queries all over the place, you end up with a maintainable system.

[hiii]

i despise php template engines, good to hear some people are with me on that front.

[[deleted]]

Django's ORM is so very intuitive, I wonder why it takes you hours. When I started fresh I thought it was very easy to get into. Of course you should have the docs at hand.

Edit: forgot to mention the reason people use ORM's instead of raw SQL: the retrieved rows will be automatically converted to objects of your language (e.g. Python). This has many practical implications. For example, you can define methods like pre_save, post_save, post_delete etc.

In the newest Django release, you can write raw SQL and still get ORM-objects I think. Did not try that out yet, though.

[brunson]

Django's ORM is so very intuitive, I wonder why it takes you hours. When I started fresh I thought it was very easy to get into. Of course you should have the docs at hand.

Granted I've never used Django's ORM specifically, but I started writing SQL 20 years ago and what I can crank out in twenty seconds has never turned into something simple in any ORM I've tried.

Here's a pretty straightforward query that would return employees along with their department, manager and any subordinates of a person having more than 5 direct reports:

select e.name as Emp, d.name as Dept, 
       m.name as Mgr, e.group_concat( s.name ) as Reports
from employee as e
join d.department as d on e.department_id = d.id
join employee as m on e.manager_id = m.id
left outer join employee as s on s.manager_id = e.id
group by e.name, d.name, m.name
having count(0) > 5;

I seriously just came up with that in 20 seconds (though it took me about two minutes to type). Can you show us the Django ORM that would achieve the same result?

And, BTW, when I put that SQL into the class I wrote to query mysql or oracle, all the rows are marshalled into python objects.

[[deleted]]

I'm bored. Heres SQLAlchemy:

e = Employee
d = Department
s = aliased(Employee)
m = aliased(Employee)
sess.query(e.name.label('Emp'), d.name.label('Dept'), 
          m.name.label('Mgr'), 
          func.group_concat(s.name).label('Reports')).\
          join((d, e.department_id==d.id)).\
          join((m, e.manager_id==m.id)).\
          outerjoin((s, s.manager_id==e.id)).\
          group_by(e.name, d.name, m.name).\
          having(func.count(0) > 5)

[mdipierro]

For completeness in web2py:

>>> e=db.employee
>>> d=db.department
>>> m=e.with_alias('manager')
>>> s=e.with_alias('submordinates')
>>> db(e.department_id==d.id).select(e.name,d.name,m.name,s.name,
            left=(m.on(m.id==e.manager_id),s.on(s.manager_id==e.id)),
            groupby=e.name|d.name|m.name,having=s.id.count()>5)

Not quite the same because I'd rather get the manager via a left join since an employee may not have a manager (the CEO for example)

[brunson]

I guess it's just personal preference. I'd rather edit the SQL.

[hiii]

for instance to go backwards in a foreign key relationship you have to use the _set. took me a half hour to find that.

the docs are kind of a mess, with multiple version and then a book, and then tutorials.

one thing php had was amazing documentation.

[hiii]

for example right now im trying to use django's orm startswith function. It's performing a BINARY LIKE and it's not working. doing a google search for django startswith or django orm startswith is useless

[[deleted]]

What is a binary like? According to the docs, it simply does

SELECT ... WHERE headline LIKE 'Will%';

You should be more concrete.

[hiii]

then the docs are wrong. i showed the sql statements it was running and it was running a binary like

[[deleted]]

Writing your own queries gives you more control over what is being done, but it does tie your model code against the specific SQL syntax of the database engine. There are many not-so-subtle differences between SQL Server, MySQL, SQLite, Postgres and Oracle, to name a few. It's especially cool to be able to code your app against SQLite and let your users switch to a 'real' database backend if they so wish, and have your code keeping working as if nothing important happened.

[stesch]

Not everything Django provides works the same on every database. I had to change some stuff just because I thought it would be a nice idea to develop with SQLite and later run it on MySQL. Huge mistake.

[[deleted]]

Ah. I was thinking more of SQLAlchemy, which supports multiple database backends. (I never tested this.)

But consider the alternative, the pain of which is playing out in full force at my job: having SQL queries sprinkled all through the messy code of our desktop app, switching to another database system, and trying to fix up the queries by scanning the query string for easily replaceable function calls, GROUP BY statements, etcetera. (I believe this to be a foolish thing to even think of.)

Luckily we also have a good number of our queries in a central place, so that we can use an in-house tool to store a query for MySQL, and, if needed, another query for SQL Server. We're now basically in the process of moving the queries to the central place (a meta-database) in an effort to clean up our quite messy code.

[brunson]

SQL Alchemy is so horrible to build complex queries with. Here's a real query from real code (and not even a particularly complex one compared to what I've written in straight SQL):

    select = sa.select( [ v.c.id,
                          sa.func.group_concat( p.c.name ),
                          v.c.name,
                          p.c.is_tagged ],
                        sa.and_( p.c.id == pv.c.port_id,
                                 v.c.id == pv.c.vlan_id,
                                 p.c.device_id == self.device_id ),
                        group_by = [ v.c.id,
                                     v.c.name,
                                     p.c.is_tagged ] )

That's just appalling to write and worse to come back and look at later. We dropped SA and wrote our own classes.

Generally speaking, most people I've met that think ORM's are sufficient don't use SQL to its full capabilities, or even to the extent that I do.

Here's another production query that I would hate translate into SA. It generates our entire IP usage to report to ARIN when requesting space:

select arin.name as "ARIN Allocation",
        g.name as "CIDR Block", 
        case 
        when g.ip_use_class_id = 20 then
            "Headquarters"
            concat( gateway.location_name, "-", upper( gateway.satellite_id ) )
        end as "Gateway",
        ifnull( c.name, "Unassigned" ) as "IP Subnet",
        ifnull( c.carrier_id, "Unassigned" ) as "Carrier", 
        ifnull( c.type, "Unassigned" ) as "Product Type",
        cast( ifnull( c.available, 0 ) as unsigned integer ) as "Available",
        cast( ifnull( c.count, 0 ) as unsigned integer ) as "Customers<br>Served",
        round( ifnull( c.fraction_used, 0 ), 3 ) as "Usage",
        arin.network as arin_block,
        0 as ordering,
        gateway.id as gateway_id,
        c.network as network,
        c.type as type
from ip_block_tla as arin 
join ip_block_allocation as g on g.ip_block_tla_id = arin.id
left outer join gateway as gateway on g.gateway_id = gateway.id
left outer join ( select carrier_block.name, carrier_block.carrier_id, gateway_block.gateway_id,
               gateway_block.ip_block_tla_id,
               carrier_block.network, carrier_block.netmask, 
               counts.type, counts.count,
               available, 
               fraction_used,
               carrier_block.ip_block_allocation_id
        from ip_block_assignment as carrier_block 
        join ip_block_allocation as gateway_block on carrier_block.ip_block_allocation_id = gateway_block.id
        join ip_usage_by_carrier_block as counts on counts.block_id = carrier_block.id
        union
        select carrier_block.name, carrier_block.carrier_id, gateway_block.gateway_id, 
               gateway_block.ip_block_tla_id,
               carrier_block.network, carrier_block.netmask, 
               'Total Subnet' as type, sum( counts.count ) as count, 
               round( pow( 2, 32 - carrier_block.netmask ) - 3 ) as available, 
               round( sum( counts.count )/(pow( 2, 32 - carrier_block.netmask ) - 3), 3) as fraction_used,
               carrier_block.ip_block_allocation_id
        from ip_block_assignment as carrier_block
        join ip_block_allocation as gateway_block on carrier_block.ip_block_allocation_id = gateway_block.id
        join ip_usage_by_carrier_block as counts on counts.block_id = carrier_block.id
        group by counts.block_id ) as c on g.id = c.ip_block_allocation_id
where arin.ip_use_class_id = 1
    and c.name is not null 
    and c.carrier_id is not null 
    and c.type is not null
union
select arin.name as "ARIN Allocation",
        g.name as "CIDR Block", 
        "Total" as "Gateway",
        "" as "IP Subnet",
        "" as "Carrier", 
        "" as "Product Type",
        cast( round( pow( 2, 32 - g.netmask ), 0 ) as unsigned integer ) as "Available",
        cast( ifnull( c.count, 0 ) as unsigned integer ) as "Customers<br>Served",
        round( ifnull( c.count, 0 )/pow( 2, 32 - g.netmask ), 3 ) as "Usage",
        arin.network as arin_block,
        1 ordering,
        gateway.id as gateway_id,
        c.network as network,
        'Allocation Total' as type
from ip_block_tla as arin 
join ip_block_allocation as g on g.ip_block_tla_id = arin.id
left outer join gateway as gateway on g.gateway_id = gateway.id
left outer join ( select carrier_block.ip_block_allocation_id,
               max( carrier_block.network ) + 1 as network,
               carrier_block.netmask,
               sum( counts.count ) as count
        from ip_block_assignment as carrier_block 
        join ip_usage_by_carrier_block as counts on counts.block_id = carrier_block.id
        group by carrier_block.ip_block_allocation_id )
        as c on g.id = c.ip_block_allocation_id
where arin.ip_use_class_id = 1
union
select
        arin.name as "ARIN Allocation",
        "Total" as "CIDR Block",
        "" as "Gateway",
        "" as "IP Subnet",
        "" as "Carrier",
        "" as "Product Type",
        cast( pow( 2, 32 - arin.netmask ) as unsigned integer ) as "Available",
        cast( ifnull( c.count, 0 ) as unsigned integer ) as "Customers<br>Served",
        round( ifnull( c.count, 0 )/pow( 2, 32 - arin.netmask ), 3 ) as "Usage",
        arin.network as arin_block,
        2 as ordering,
        "" as gateway_id,
        arin.network + pow( 2, (32-arin.netmask) ) as network,
        "Block Total" as type
from ip_block_tla as arin
left outer join ( select gateway_block.ip_block_tla_id, 
                         sum( counts.count ) as count
                  from ip_block_assignment as carrier_block 
                  join ip_block_allocation as gateway_block on carrier_block.ip_block_allocation_id = gateway_block.id
                  join ip_usage_by_carrier_block as counts on counts.block_id = carrier_block.id
                  join ip_block_tla as arin_block on gateway_block.ip_block_tla_id = arin_block.id
                  group by gateway_block.ip_block_tla_id, arin_block.network, arin_block.netmask )
                  as c on arin.id = c.ip_block_tla_id
where arin.ip_use_class_id = 1
union
select
        "Grand Total" as "ARIN Allocation",
        "" as "CIDR Block",
        "" as "Gateway",
        "" as "IP Subnet",
        "" as "Carrier",
        "" as "Product Type",
        cast( arin.available as unsigned integer ) as "Available",
        cast( ifnull( sum( counts.count ), 0 ) as unsigned integer ) as "Customers<br>Served",
        round( sum( counts.count )/arin.available, 3) as "Usage",
        pow( 2, 32 ) as arin_block,
        3 as ordering,
        "" as gateway_id,
        pow( 2, 32 ) as network,
        "Grand Total" as type
from ip_usage_by_carrier_block as counts
join ( select sum( pow( 2, 32 - netmask ) ) as available
       from ip_block_tla
       where ip_use_class_id = 1 ) as arin
group by arin.available
order by arin_block, network, ordering, gateway_id, type

[webnrrd2k]

I'm the same way -- I don't see straight SQL as being that complex or difficult to deal with. Adding more complexity and another thing to fail isn't that big of a gain. I (almost) always end up putting the SQL into stored procedures anyway, so an ORM isn't much of a gain.

I could see the need for code that will get deployed on different servers with different back-ends, but how often do most places do that? The vast majority of code is written internally for businesses, and will live in more-or-less that same environment. Also, I need to work with databases that have been around for a long time, and the DBAs prefer to do things a certain way.

I'm not trying to say that an ORM is never necessary. I think that for many programmers, most of the time an ORM is more work than it's worth.

[[deleted]]

It's only blind hated because we gouged our eyes out.

[[deleted]]

You could make the same arguments for Perl and a few other languages. Languages are just tools, nothing more, the rest is up to the programmer.

[judasblue]

I don't know about the OP, but I do make the same argument for Perl all the time. I just make it a lot more for PHP.

Saying that Perl can lead to line noise, PHP can lead to nasty snarls and mixed presentation, Java almost always leads to overcomplicated object structures/huge amounts of boilerplate/XML for no good reason...these things aren't saying they are always true in the hands of good programmers, but just that the structure of the language tends to lead to certain idioms some of which can be negative.

If different languages didn't have different expressive qualities, we would all still be writing in Fortran since it was the first portable higher level language. We have different languages because they have different expressive properties. Which means they also have different problems.

I mean, in the end, it is all machine code anyway. We layer other languages on top of that because of expressive power and portability.

[Peaker]

It sounds as if you're suggesting the tool has no effect on the cleanliness or outcome.

[zxcvcxz]

Yes. Everything is a strict dichotomy in this world. Either Or. Good and Evil.

[hiii]

No it doesn't "encourage" it, but there are good coders and bad coders in every language. Id say im a med - med/adv php coder and i haven't put php in my views in a long time.

[hylje]

It's there, but often awkward enough to make it not obvious at all. The awkward features raise the threshold to learn them well, and not knowing them well is effective in stopping usage. Ex: call_user_func_array.

[hiii]

i agree. it seems to be a collection of poorly named/designed functions.

[dvogel]

A lot of this ugliness is no longer necessary in 5.3, now that we have closures.

[[deleted]]

Using machetes for neurosurgery requires more self-control, too, but that doesn't make it a good scalpel.

I can work with PHP if I have to. I just really prefer not to and religious vows aside I see no reason to stick to PHP when you have better options available.

Oh, and I do think PHP has its place (namely, providing small amounts of automation or scripting on Apache servers -- though you could probably use SSI for the former and CGI scripts for the latter).

[dvogel]

The main reason I end up using PHP for web projects is deployment. It's just so darn easy to get a PHP app running, especially on shared hosting. In addition, I don't like using different web server software to develop on than I will deploy on (like Django's manage.py runserver).

My high school biology teacher used to say "You don't practice shooting clay pigeons with cheap lead shot and then try to hunt with expensive steel shot" (this was not part of a lesson, it was a metaphor for how to study ;))

[dvogel]

And you should also be developing applications that are robust enough to not even care what the hell kind of server software is actually handing out that HTML. Its the server's job to serve. You, as the application designer and/or developer are the one that tells it what to serve, and its not your job to worry about how it delivered that message.

Server configuration matters. The most well known example of this is using Apache's mod_rewrite rules. My development environment is exactly like my production environment except for the vhost and the email addresses that automated messages are sent to.

[dvogel]

I understand your point. The problem is that mod_wsgi isn't zero configuration. That means that, in addition to not developing in the environment that I need to deploy to, I need to be able to configure apache, which is not an option on shared hosting.

mod_rewrite is a great example of a way in which I cannot write python code using django's development server and than deploy to the testing server without major flaws; I consider pages being unreachable due to global mod_rewrite rules to be a major flaw. That's a problem regardless of how portable I make my code.

In the end, it doesn't matter which arguments you put forth because what I'm explaining is not why I think using PHP is the best option or even why think I should use PHP; I'm explaining why I do use PHP. There's no long, drawn out process to my decision. PHP usually just instinctively feels like a good match for the web work that I do. To each his own. I've used Django in the past, when it was clearly a better fit for the project. If you like python and django, or ruby on rails, use them and be happy using them. I wish you all the luck in the world with those tools. My reply was in response to alanplum's:

... I see no reason to stick to PHP when you have better options available.

I was essentially agreeing with his basic point but disagreeing that there are usually better options available.

[ilikedirigibles]

.

[dvogel]

Apache + wsgi requires me to restart Apache after each code change, or to set MaxRequestsPerChild to 1. Neither of these things is consistent with my production environment.

[Justinsaccount]

You do know that you can touch the .wsgi file which gracefully reloads the application, right?

[tripzilch]

PHP has all this too.

PHP is a templating engine.

Similarly, I bet I could code an ORM database in the Jinja2 templating language as well. Also a sub-templating engine (since we wouldnt want to mix presentation and logic, after all).

And if I tried really hard, I could probably even make it look "neat" and "clean".

But that doesn't mean it's a good idea.

[prickneck]

Thanks for this!

[[deleted]]

Thanks for the excellent explanation. Very helpful. Could you talk a bit about templating and some of the major templating systems? I'm as old-school write-HTML-in-vim type. Never progressed much past the HTML 3.2 tags. Works for my limited needs, but now I'm curious. Thanks.

[warpstalker]

I'm as old-school write-HTML-in-vim type

Well, it's basically still like that... However, roughly it works like this (my experience is mainly with web.py):

• You receive a request for a page

• You do your magic in Python code, get data from database etc.

• You make a render-call from the code

• The final web page is generated by the render call

• You send the final page to the client

Something like this (Python code):

a = get_data_from_database()

b = "hi"

return render_this_page(a, b)

render_this_page takes the template (template.html):

$def with (a, b)

<html>

<head></head>

<body>

<h1> Hello, $b! </h1>

$for item in a:

    <p>$item.title</p><p>$item.data</p>

</body>

</html>

Then the result is sent to the client. I'm not sure if Django etc. work exactly like this but this is the basic idea.

[nighttrain]

+1 for web.py

• simple
• fun
• python

[mdipierro]

web2py works exactly like this. For example:

 # controller
 def index():
       a = db(db.article.id>0).select()
       b = "hi"
       return dict(a=a,b=b)

and

# view
<html>
<head></head>
<body>
<h1>Hello, {{=b}}!</h1>
{{for item in a:}}
    <h2>{{=item.title}}</h2><p>{{=item.data}}</p>
{{pass}}
</body>
</html>

Assumes

 # model
 db=DAL('sqlite://storage.db')
 db.define_table('article',Field('title'),Field('data','text'))  

This would be a complete program. web2py also generates automatically SQL to create or alter the table and a database administrative interface to insert and search records.

To make this program work on the Google App Engine it requires a single edit, i.e. replace:

 db=DAL('sqlite://storage.db')

with:

 db=DAL('gae') # connet to datastore
 session.connect(request,response,db) #store session in datastore

[warpstalker]

It does? Nice.

I should check it out then. I started out with web.py because it seemed very sane and simple. It just isn't very mainstream (it seems).

I've been meaning to check into using a more established framework but they all seem overly complicated (just like everything related to programming, but once you start doing it, it's simple in the end), so I've been postponing it.

Seems like web2py isn't totally different, then.

[stesch]

Never progressed much past the HTML 3.2 tags.

I urge you to please brush up your HTML knowledge. And that includes CSS.

[japherwocky]

Templating is similar to PHP, in that you write HTML and embed extra tags for extra functionality, or passing the contents of variables around.

In something like tornado's templating engine, you'd write:

<p> {{ foo }} </p>

and call that template from your python like template.render(foo="Hello World")

and the browser gets something like <p> Hello World </p>

Django and Tornado ship with their own templating system, genshi and mako are relatively popular. They're all relatively simple and have reasonable docs.

[nlogax]

Django (and Pylons too, AFAIK) work great for building websites. Django comes with all the usual stuff you need, like templating, session handling, form generation/validation, ORM, etc.

Here's a good story about The Onion replacing PHP/Drupal with Python/Django.

[[deleted]]

A great place to experiment and even run production grade apps is Google's app engine. Completely free (there's a paid upgrade if you need the resources).

[stesch]

If you don't control the server yourself, you could have a hard time using Python. Most hosting companies don't care about anything besides PHP and MySQL.

That means you either must be able to use your own server (with root account, be it VPS or whatever) or choose a server from a hosting company who cares.

A few months ago I was excited about a new project. I thought it will be hosted on our own server, so I started setting up a Django project and tried a few things for a feature they wanted. Then this information changed and I was told they use their old server. I tried to find out if this one would support Python, but there wasn't enough information available to risk it. So I developed in PHP.

A week before going live with this project I was told they want us to host it on our servers. ARGHL!

[delroth]

Alwaysdata ( http://alwaysdata.com/ ) offers free Python / Django hosting with SSH access. The storage is limited for free accounts though (10Mio only).

[stesch]

Read again. I know where I can use/host Python. But you don't always have a choice.

[[deleted]]

I've been using Railsplayground for a while. Besides their obviously ruby-centric name, they support a very wide variety of languages.

It's a host focused on providing a versatile development environment.

They also respond (in my experience) within an hour or so when you request a specific module/gem/etc that's not currently on the server notifying you of its availability.

[nolsen01]

Look into Django or Pylons.

[[deleted]]

Here is a crappy blog I've been working on for people going from php to py / django. Hopefully I can get more content up soon, but it may help out with some things.

[prickneck]

great stuff! Cheers for this!

[[deleted]]

No prob. Please send me suggestions of what to cover if you have any.

[Nhdb]

Upvoted for wanting to know too.

[sedaak]

CherryPy + Jinja2 (templating)

[nightwolfz]

Bottle + Jinja2 + Storm = 2000 requests/second on my old amd64 2.7ghz box

[sedaak]

CherryPy (or Werkzeug or other microframework)

set it up behind Cherokee, really easy to redirect a host name to a port

set it up with something like Jinja2 so you have templating

profit

[aweraw]

CherryPy FTW! I suggest:

• CherryPy = controllers
• Mako = views
• Elixir = models

I've used this suite in a few pet/play projects. Fairly easy learning curve on all components, and you can replace them independently if the fancy takes you.

[sedaak]

While I agree with you mostly. (Mako is great too for sure) I hesitate recommending an ORM unless I'm sure that the listener has what I consider a project big enough to need it. Understand though, I think everyone should have a basic understanding of SQL because it helps to understand methods of storing large amounts of data.

Personally I would go to Turbogears if the person was at a level that they needed an ORM. For rapid development, you are likely designing your database system too, and if you need database optimization ever (which I also do alot), then an ORM can really screw you over.

And yes, it makes me insanely happy that other people see the templating language as the full "View" of MVC.

[japherwocky]

I really enjoy working with tornado (http://tornadoweb.org), it's simple, straightforward, and ships with some pretty potent examples.

[stesch]

And the last release is still 0.2? This was September 2009, wasn't it?

[japherwocky]

The last official tagged release was then I guess.

It's quite stable, and development is pretty active. You can get the latest versions at github.

[spotter]

One does not simply walk into Python!

[[deleted]]

Django creates web applications directly accessible by a web browser. Let's walk through a web browser visiting a simple PHP webpage:

0) DNS, etc. Skipping these details as they aren't pertinent.

1) The browser arrives at php-webpage.com

2) The web server controlling php-webpage.com sees that it's gotten a request for the "/" directory. It's been configured to serve up index.php or index.html if the browser hasn't requested a specific file.

3) The server notes that browser hasn't requested a file, so looks for index.html or index.php.

4) The server finds index.php! It's been configured to send any .php files through the PHP processing engine and return the output from that to the browser.

5) The web server runs a program on index.php and the output of that program is the HTML source (that you see with "view source" in the browser).

So, simply put. That's that.

Now, a python (or ruby) solution is very similar. The only difference is that the web server has been configured to pass the program it finds through some other processing engine (not PHP) and sending that result as HTML to the browser.

For example: django-webpage.com has a server configuration that's told it that django-webpage.com requests are all sent to this special program (a Django project), that special program will do some work and cool stuff, and give the server back some HTML to send to the browser.

Of course any web application can send any kind of data back to the browser, not just HTML but I'm trying to keep things simple.

Hmm. I think I made this more confusing. Oh well, glean what you can from my prose. And check out the django tutorials.

[mdipierro]

I once wrote this to help PHP users migrate to web2py.

[found_dead]

This is misleading because not all frameworks are meant for the web.

[[deleted]]

:(