I'm pretty proficient in PHP, but want to try something new.
I'm also know a bit of Python, enough to do the basics of the basics, but haven't used in a web design type situation.
I've just written this, which works:
#!/usr/bin/python
def main():
print "Content-type: text/html"
print
print "<html><head>"
print "<title>Hello World from Python</title>"
print "</head><body>"
print "Hello World!"
print "</body></html>"
if __name__ == "__main__":
main()
Thing is, that this seems pretty cumbersome. Without using something huge like django, what's the best way to write scripts that can process get and post?
Your question was about basic CGI scripting, looking at your example, but it seems like everyone has chosen to answer it with "use my favorite framework". Let's try a different approach.
If you're looking for a direct replacement for what you wrote above (ie. CGI scripting), then you're probably looking for the cgi module. It's a part of the Python standard library. Complimentary functionality is available in urllib and urllib2. You might also be interested in BaseHTTPServer and SimpleHTTPServer, also part of the standard library.
Getting into more interesting territory, wsgiref gives you the basics of a WSGI interface, at which point you probably want to start thinking about more "frameworky" (is that a word?) things like web.py, Django, Pylons, CherryPy, etc, as others have mentioned.
As far as full frameworks go I believe Django is relatively small.
If you really want lightweight, though, check out web.py, CherryPy, Pylons and web2py.
I think the crowd favorite from the above is Pylons, but I am a Django man so I can't say much else.
For more on lightweight Python frameworks, check out this question.
There are a couple of web frameworks available in python, that will relieve you from most of the work
Django
Pylons (and the new TurboGears, based on it).
Web2py
CherryPy (and the old TurboGears, based on it)
I do not feel Django as "big" as you say; however, I think that Pylons and CherryPy may be a better answer to your question. CherryPy seems simpler,. but seems also a bit "passé", while Pylons is under active development.
For Pylons, there is also an interesting Pylons book, available online.
In Python, the way to produce a website is to use a framework. Most of the popular (and actively maintained/supported) frameworks have already been mentioned.
In general, I do not view Djano or Turbogears as "huge", I view them as "complete." Each will let you build a database backed, dynamic website. The preference for one over the other is more about style than it is about features.
Zope on the other hand, does feel "big". Zope is also "enterprise" class in terms of the features that are included out of the box. One very nice thing is that you can use the ZODB (Zope Object Database) without using the rest of Zope.
It would certainly help if we knew what kinds of websites you were interested in developing, as that might help to narrow the suggestions.
In web2py the previous code would be
in controller default.py:
def main():
return dict(message="Hello World")
in view default/main.html:
<html><head>
<title>Hello World from Python</title>
</head><body>
{{=message}}
</body></html>
nothing else, no installation, no configuration, you can edit the two files above directly on the web via the admin interface. web2py is based on wsgi but works also with cgi, mod_python, mod_proxy and fastcgi if mod_wsgi is not available.
I really love django and it doesn't seem to me that is huge. It is very powerful but not huge.
If you want to start playing with http and python, the simplest thing is the BaseHttpServer provided in the standard library. see http://docs.python.org/library/basehttpserver.html for details
I agree with Paolo - Django is pretty small and the way to go - but if you are not down with that I would add to TurboGears to the list
If you are looking for a framework take a look at this list: Python Web Frameworks
If you need small script(-s) or one time job script, might be plain CGI module is going to be enough - CGI Scripts and cgi module itself.
I would recommend you to stick to some framework if you want to create something more then static pages and simple forms. Django is I believe most popular and most supported.
What is "huge" is a matter of taste, but Django is a "full stack" framework, that includes everything from an ORM, to templates to well, loads of things. So it's not small (although smaller than Grok and Zope3, other full-stack python web frameworks).
But there are also plenty of really small and minimalistic web frameworks, that do nothing than provide a framework for the web part. Many have been mentioned above. To the list I must add BFG and Bobo. Both utterly minimal, but still useful and flexible.
http://bfg.repoze.org/
http://bobo.digicool.com/
Related
Any pointers, advice on implementing a REST API on App Engine with Python? Using webapp for the application itself.
What I currently know is that I can:
hack up my own webapp handlers for handling REST-like URIs, but this seems to lose its elegance for larger amounts of resources. I mean, it's simple when it comes to temperature/atlanta, but not so much* for even a rather simple /users/alice/address/work (though do keep in mind that I'm not saying this after having implemented that, just after spending some time trying to design an appropriate handler, so my perception may be off).
use the REST functionality provided by one of the bigger Python web frameworks out there. I have some unexplainable sympathy towards web2py, but, since it's not used for the project, bundling it with the application just to provide some REST functionality seems.. overkill?
(Huh, looks like I don't like any of these approaches. Tough.)
So here's me asking: what advice, preferably based on experience, would you have for me here? What are my options, is my view of them correct, did I miss something?
Thanks in advance.
I had a similar issue. Wanting to quickly get my DataStore exposed via REST to WebApps.
Found: AppEngine REST Server.
I have only used it lightly so far, but it certainly appears to be very useful with a small amount of work. And it does use webapp as you suggested.
ProtoRPC is bundled with the SDK, and it is robust and actively developed (however experimental). Although I think the source code itself is a little convoluted, the feature-set is pretty complete and it was made by someone with experience in creating this kind of library. It supports transmiting using JSON, ProtocolBuffer and URL-encoded formats.
Also, you can create APIs that work on the server side and client side -- it defines a 'message' protocol with implementations in Python and JavaScript. I used other "RESTful" Python libraries, but no other provided this consistency out of the box.
Here is the project page and here is the mailing list.
Edit: maybe their documentation is lacking some keywords, but just to be clear: one or the purposes of ProtoRPC is to provide a solid foundation to create REST services.
I've been learning python for use in ArcGIS and some other non-web applications. However, now that I've taken on building a personal website I am interested in using it for web development (as it is the only scripting language I currently know).
I've noticed that there are a lot of these things called "frameworks", such as Django. From what I understand they are just a collection of packages to save you from re-inventing the wheel but I don't really know how they work.
Furthermore, I do not like GUIs, if I need a framework I would like to find one that could be used through a terminal, starts out simple and can be scaled for more complexity when I'm ready. Any advice or ideas on frameworks and why I would want to use one?
The Python web frameworks have nothing to do with GUIs, and can all be used via the terminal.
The benefits of a framework, as you say, are all to do with making your life easier by supplying the components you need to build a website: the main ones are database interaction through an ORM, a templating system, and URL routing. On top of that, the big frameworks also included optional extras like user authentication, administration interface, and so on.
Personally I like Django, but your mileage may vary: I would say, though, that whatever you do with Python and the web will require some sort of framework, even if it's one of the absolute minimal ones like Flask which basically do just the routing part. There's simply no point in writing all this stuff from scratch when it's been done for you.
I'd second the post above: Django is a great framework and will save you loads of time in the long run.
Pretty much every challenge you'll come across when writing a web application will already have been solved, e.g. How do I send emails? What about an admin interface to edit the data? User security?
In my view picking the best framework is all about the ecosystem around that framework. How well used is it? Is it discussed widely on the internet? Have others encountered, and solved, the problems I'm facing?
In terms of where you start, see the Django Tutorial here:
http://docs.djangoproject.com/en/1.2/intro/tutorial01/
If you think Django offers you too much, I'd recommend that you take a look at CherryPy just to compare the different, and much simpler, approach.
With Python, you've got lots of options. To start, I would recommend looking here -- it explains the basics and provides a fairly complete list of frameworks.
If you're looking for something that starts out simple but can also handle more complexity, then you should take a look at web2py. It requires no installation or configuration, has no dependencies, and includes a web server and a relational database. It also includes an optional web-based integrated development environment and admin interface, but you can work through the terminal instead if you prefer.
It's very easy to learn and was designed for ease of use, faster development, and security. You can get a lot done with very little code thanks to the included scaffolding app along with many sensible default behaviors. As things get more complex, web2py can handle it, as it is a well-integrated full-stack framework with lots of built-in functionality, including a database abstraction layer, form handling and validation, access control, web services, and easy Ajax integration.
Personnally, I don't use any framework, I write either from scratch on BaseHTTPServer, or using WSGI (with mod_wsgi).
It is a bit long to write the skeleton, but I think it is faster (I mean at runtime), there is less constraints, and there is lesser to learn.
I'm really interested in learning Python for web development. Can anyone point me in the right direction? I've been looking at stuff on Google, but haven't really found anything that shows proper documentation and how to get started. Any recommended frameworks? Tutorials?
I've been doing PHP for 5 years now, so I just want to try something new.
Django is probably the best starting point. It's got great documentation and an easy tutorial (at http://djangoproject.com/) and a free online book too (http://www.djangobook.com/).
Web Server Gateway Interface
About
http://www.wsgi.org/en/latest/index.html
http://en.wikipedia.org/wiki/Web_Server_Gateway_Interface
Tutorials
http://webpython.codepoint.net/wsgi_tutorial
http://lucumr.pocoo.org/2007/5/21/getting-started-with-wsgi/
http://archimedeanco.com/wsgi-tutorial/
There are three major parts to python web frameworks, in my experience. From the front to back:
Views/Templates: Application frameworks don't function as independent scripts - instead, you map paths to python functions or objects which return html. To generate the html you probably need templates (aka views). Check out Cheetah.
Application framework/Server: There are plenty. CherryPy is my favorite, and is good for understanding how a python application server works because a) it's simple and b) unlike django and others, it is just the application server and doesn't include a templating engine or a database abstraction layer.
Database layer: I've actually never used it, but everyone seems to like SQLAlchemy. I prefer, in simple applications, executing SQL directly using a tool like psycopg2 (for postgres).
You can try Django. It's easy to learn, and it works with GAE (though the default version is 0.96, a little bit old, but you can change it). And there's a video about rapid development (by Guido Van Rossum) that goes through the basics of setting up a Django project in App Engine.
I am very new to python and having to get into this stuff for a simple program to integrate with an ASP.NET application that I am building. The pseudo code is as follows.
Get two parameters from request. (A ASP.NET will be calling this url by POST and sending two parameters)
Internally execute some business logic and build some response.
Write the response back so that the ASP.NET app can proceed.
Step 2 and 3 are already in place and working too but not able to find a solution for Step 1 (I know it should be very simple and know how to do it in Java/.NET/PHP and RoR but not in Python and the online docs/tutorials are not helping my cause). I am running python on apache using mod_python.
Any help here is greatly appreciated. Thanks in advance
Vijay
Here is a good beginner's tutorial for mod_python.
As far as I understand your question you have a mod_python-based script and you want to read a POST parameter. Therefore you only have to use the form object which is automatically provided by mod_python:
myparameter = form.getfirst("name_of_the_post_parameter")
You can find the documentation over here.
Note that this solution is when your server is configured with PythonHandler mod_python.psp which will allow you to use "Python Server Pages" (special <% %> tags, automatically created variables like form, ...). If you're writing a normal mod_python handler, then it would look something like that:
from mod_python import util
def handler(req):
form = util.FieldStorage(req, keep_blank_values=1)
myparameter = form.getfirst("name_of_the_post_parameter")
...other stuff...
"I know it should be very simple and know how to do it in Java/.NET/PHP and RoR but not in Python"
Well, it's not simple in Python -- the language.
It is simple in many Python web frameworks.
Don't make the mistake of comparing Python (the language) with PHP (the web framework) or RoR (the web framework).
Python, like Java or VB or Ruby, is a programming language. Not a web framework.
To get stuff from Apache into Python you have three choices.
A CGI script. A dreadful choice.
mod_python. Not a great choice.
mod_wsgi. A much better choice.
If you're stuck with mod_python -- because this is homework, for instance -- you'll need to read a mod_python tutorial in addition to a python tutorial.
This, for example, seems to be what you're doing. http://www.modpython.org/live/current/doc-html/tut-pub.html
I'm just starting out with Python and have practiced so far in the IDLE interface. Now I'd like to configure Python with MAMP so I can start creating really basic webapps — using Python inside HTML, or well, vice-versa. (I'm assuming HTML is allowed in Python, just like PHP? If not, are there any modules/template engines for that?)
What modules do I need to install to run .py from my localhost? Googling a bit, it seems there're various methods — mod_python, FastCGI etc.. which one should I use and how to install it with MAMP Pro 1.8.2?
Many thanks
I think probably the easiest way for you to get started is to work with something like Django. It's a top-to-bottom web development stack which provides you with everything you need to develop and run a backend server. Things can be very simple in that world, no need to mess around with mod_python or FastCGI unless you really have the need.
It's also nice because it conforms to WSGI, which is a Python standard which allows you to plug together unrelated bits of reusable code to add specific functionality to your web app when needed (say for example on-the-fly gzip compression, or OpenID authentication). Once you have outgrown the default Django stack, or want to change something specific you can go down this road if you want.
Those are a few pointers to get you started. You could also look at other alternative frameworks such as TurboGears or paste if you wanted but Django is a great way to get something up and running quickly. Anyway, I'm sure you'll enjoy the experience: WSGI makes it a real joy knocking up web apps with the wealth of Python code you'll find on the web.
[edit: you may find it helpful to browse some of the may Django related questions here on stack-overflow if you run into problems]
You asked whether HTML is allowed within Python, which indicates that you still think too much in PHP terms about it. Contrary to PHP, Python was not designed to create dynamic web-pages. Instead, it was designed as a stand-alone, general-purpose programming language. Therefore you will not be able to put HTML into Python. There are some templating libraries which allow you to go the other way around, somewhat, but that's a completely different issue.
With things like Django or TurboGears or all the other web-frameworks, you essentially set up a small, stand-alone web-server (which comes bundled with the framework so you don't have to do anything), tell the server which function should handle what URL and then write those functions. In the simplest case, each URL you specify has its own function.
That 'handler function' (or 'view function' in Django terminology) receives a request object in which interesting info about the just-received request is contained. It then does whatever processing is required (a DB query for example). Finally, it produces some output, which is returned to the client. A typical way to get the output is to have some data passed to a template where it is rendered together with some HTML.
So, the HTML is separated in a template (in the typical case) and is not in the Python code.
About Python 3: I think you will find that the vast majority of all Python development going on in the world is still with Python 2.*. As others have pointed out here, Python 3 is just coming out, most of the good stuff is not available for it yet, and you shouldn't be bothered about that.
My advise: Grab yourself Python 2.6 and Django 1.1 and dive in. It's fun.
Django is definitely not the easiest way.
check out pylons. http://pylonshq.com/
also check sqlalchemy for sql related stuff. Very cool library.
On the other hand, you can always start with something very simple like mako for templating. http://www.makotemplates.org/