For some quick background, I'm an XHTML/CSS guy with some basic PHP knowledge. I'm trying to dip my feet into the Python pool, and so far understand how to start simple_server and access a simple Hello World return in the same .py file. This is the extent of what I understand though, heh.
How do I integrate the simple_server and your basic XHTML/CSS files? I want to start the server and automagically call, for instance, index.py (does it need to be .py?). Obviously within the index file I would have my markup and stylesheet and I would operate it like a normal site at that point.
My eventual goal is to get a basic message board going (post, edit, delete, user sessions). I realize I'll need access to a database, and I know my way around MySQL enough to not have to worry about those portions.
Thanks for the help.
EDIT: Allow me to clarify my goal, as I have been told Python does a LOT more than PHP. My goal is to begin building simple web applications into my pre-existing static XHTML pages. Obviously with PHP, you simply make sure its installed on your server and you start writing the code. I'd like to know how different Python is in that sense, and what I have to do to, say, write a basic message board in Python.
The other answers give good recommendations for what you probably want to do towards your "eventual goal", but, if you first want to persist with wsgiref.simple_server for an instructive while, you can do that too. WSGI is the crucial "glue" between web servers (not just the simple one in wsgiref of course -- real ones, too, such as Apache or Nginx [both with respective modules called mod_wsgi] as well as, for example, Google App Engine -- that one offers WSGI, too, as its fundamental API) and web applications (and frameworks that make it easier to write such applications).
Everybody's recommending various frameworks to you, but understanding WSGI can't hurt (since it will underlie whatever framework you eventually choose). And for the purpose of such understanding wsgiref.simple_server will serve you for a while longer, if you wish.
Essentially, what you want to do is write a WSGI app -- a function or class that takes two parameters (an "enviroment" dictionary, and a "start response" callable that it must call back with status and headers before returning the response's body). Your "WSGI app" can open your index.py or whatever else it wants to prep the status, headers and body it returns.
There's much more to WSGI (the middleware concept is particularly powerful), though of course you don't have to understand it very deeply -- only as deeply as you care to! See wsgi.org for tutorials &c. Gardner's two-part article, I think, is especially interesting.
Once (and if that's your choice) you understand WSGI, you can better decide whether you want it all hidden in a higher level framework such as Django (so you can focus on application-level issues instead) or use a very light and modular toolbox of WSGI utilities such as Werkzeug -- or anything in-between!-)
I would recommend Django.
"Obviously with PHP, you simply make sure its installed on your server and you start writing the code."
Not true with Python. Python is just a language, not an Apache plug-in like PHP.
Generally, you can use something like mod_wsgi to create a Python plug-in for Apache. What you find is that web page processing involves a lot of steps, none of which are part of the Python language.
You must use either extension libraries or a framework to process web requests in Python. [At this point, some PHP folks ask why Python is so popular. And the reason is because you have choices of which library or framework to use.]
PHP parses the request and allows you to embed code in the resulting page.
Python frameworks -- generally -- do not work this way. Most Python frameworks break the operation down into several steps.
Parsing the URL and locating an appropriate piece of code.
Running the code to get a result data objects.
Interpolating the resulting data objects into HTML templates.
"My goal is to begin building simple web applications into my pre-existing static XHTML pages."
Let's look at how you'd do this in Django.
Create a Django project.
Create a Django app.
Transform your XTHML pages into Django templates. Pull out the dynamic content and put in {{ somevariable }} markers. Depending on what the dynamic content is, this can be simple or rather complex.
Define URL to View function mappings in your urls.py file.
Define view functions in your views.py file. These view functions create the dynamic content that goes in the template, and which template to render.
At that point, you should be able to start the server, start a browser, pick a URL and see your template rendered.
"write a basic message board in Python."
Let's look at how you'd do this in Django.
Create a Django project.
Create a Django app.
Define your data model in models.py
Write unit tests in tests.py. Test your model's methods to be sure they all work properly.
Play with the built-in admin pages.
Create Django templates.
Define URL to View function mappings in your urls.py file.
Define view functions in your views.py file. These view functions create the dynamic content that goes in the template, and which template to render.
Take a look at CherryPy. It's a nice http framework.
It depends on what you want to achieve,
a) do you want to just write a web application without worrying too much abt what goes in the background, how request are being handled, or templates being rendered than go for a goo webframework, there are many choices simple http server is NOT one of them. e.g. use django, turbogears, webpy, cheerpy, pylons etc etc
see http://wiki.python.org/moin/WebFrameworks for full list
b) if you want to develope a simple web framework from start so that you understand internals and improve you knowledge of python, then I will suggest use simple http server
see
how can you create a URL scheme so that URLs are dispatched to correct python function,
see how can you render a html
template e.g. containing place
holder variables $title etc which
you can convert to string using
string.Template
b) would be difficult but interesting exercise to do, a) will get you started and you may be writing web apps in couple of days
Related
I’m creating a big project with Django and wondering if it is sensible to use the HTML template structure for my front end or should I implement something like React? What are each of its benefits? Is it perfectly reasonable to use HTML templates for a big project? Any advice?
Django templates are quite fully featured, and performant, and I'd use them if I could meet the requirements in my project with them alone. Adding react will increase the tooling you'll need and have to maintain, so my team only introduced it after we started to need user interfaces that were react-like (it started when we implemented an in-app to do list). So your project requirements will really dictate if you want to invest additional development and devops energy into react in order to have a more instant-update/native-app-like feel, or not.
If you are unsure, I'd recommend starting with templates and introducing react later. It's entirely possible to run an app that uses templates for 90% of your app and react only where it's needed (we do this).
The thing with React is you need to have a good API in between your back-end and your front-end. I would recommend Django Rest Framework for that. Anyway, templates are nice to quickly get something up and running, something that is mostly display centered and you don't have to do too much scripting. React makes it easier to have a heavier front-end. However, templates can handle a lot of front end as well, just you won't get access to any of the nice benefits of React. I have used templates for a big project, and it worked nicely. I didn't have to build an API, and the templates easily interacted with my back-end. I am not sure exactly what kind of project you are doing, so these are just my recommendations.
What is the best way to implement isomorphic react app using webpack with python as backend to serve
Following features are required to be implemented
1. React router
2. Redux store
By Isomorphic, I understand you mean both rendered on the server & on the client - so the first access of the site will return static HTML and a javascript bundle which then replaces the static HTML with the react-rendered version.
Usually this would mean running javascript on the server too with Node.js. This means you can render your JSX / React templates / components on the server and send them as static HTML to the user. If you're working with Python on the server, you cannot use your JSX / Javascript templating & logic on the server, so you'll need to duplicate it in Python.
So since you have to do it all twice - you first need to work out which one you want to do first. Either in Python first, or Javascript.
You can either start by building the whole application server-side-rendered, and then have javascript take over, or build a fully javascript application, and render the first views with Python.
Personally, for content-driven sites, I prefer building a server-side rendered application with Django (the most used Python Web Framework), and then adding Javascript on top once it's all fully working as a javascriptless site. This has the advantage of working even when javascript is disabled, and ensures you have good URLs, etc.
Of course, if it's a really complex application in terms of user interaction, you'll need to do it the other way.
I recomend looking into Django first, Here is a great tutorial from django-girls. However, if you want to go the mainly-JS route, here's some ideas:
Javascript First
Probably the best way is to first design your data structure(s), and make a REST api for your data. (e.g. /api/1.0/cars/rustbucket_94 which sends JSON data.)
Next, figure out your user-facing URL schema, and work out which REST endpoints need to be pulled in to get those pages. (How the URLs should look to the end users. e.g. /cars/rustbucket_94.html)
Design your React app as normal, using those REST / JSON endpoints, and the react router to show it correctly.
Once you have your whole react app working, you can now build a server-side rendered version of the whole thing, which you'll need to re-implement from scratch, and can either access the data through the JSON endpoints (slow) or by making the queries itself inside the pages.
The Python side
Which Python Framework to use on the backend?
I'd recommend Django to start with. It's very capable and can do ANYTHING you want it too. You probably need the Django REST framework too. There are other options available, but this will be the quickest way to get something secure and sane running.
Getting Django to work nicely with your webpack / react workflow is not too complex. There are projects like Django-Webpack-Loader and various tutorials about it online showing how to use it.
Good luck.
Hi I'm working on a project based on Django Cms
DJango Cms
Most of the templates ara generated via an APi call in ajax.. I wondered if is possible to generate an HTML static file from the original template file in order to avoid dynamic calls.
Short answer: Yes.
Long answer: It depends.
There's little stopping you from just creating static HTML pages (you could for example just use wget to crawl you website. However note that this only works if your content is not dynamic, as in, it doesn't depend on whether a user is logged in or not etc. If you only use plugins that always have the same output, regardless of the request, then it'll work.
Since Django CMS gives you a lot of power to write highly dynamic plugins, there's no built-in way of generating these static pages (the chances of someone using it without realizing the drawbacks are high).
I have a new job and a huge django project (15 apps, more than 30 loc). It's pretty hard to understand it's architecture from scratch. Are there any techniques to simplify my work in the beginning? sometimes it's even hard to understand where to find a form or a view that I need... thnx in advance.
When I come to this kind of problem I open up a notebook and answer the following:
1. Infrastructure
Server configuration, OS etc
Check out the database type (mysql, postgres, nosql)
External APIS (e.g Facebook Connect)
2. Backend
Write a simple description
Write its input/output from user (try to be thorough; which fields are required and which aren't)
Write its FK and its relation to any other apps (and why)
List down each plugin the app is using. And for what purpose. For example in rails I'd write: 'gem will_paginate - To display guestbook app results on several pages'
3. Frontend
Check out the JS framework
Check the main stylesheet files (for the template)
The main html/haml (etc) files for creating a new template based page.
When you are done doing that. I think you are much more prepared and able go deeper developing/debugging the app. Good luck.
Use this http://packages.python.org/django-extensions/graph_models.html
to generate the Relationship diagrams from the models so that you can visually see how the models are related to each other. This will give you nice idea about the app
1) Try to install the site from scratch. You will find what external apps are needed for the site to run.
2) Reverse engineer. Browse through the site and try to find out what you have to do to change something to that page. Start with the url, look up in urls.py, read the view, check the model. Are there any hints to other processes?
3) Try to write down everything you don't understand, and document the answers for future reference.
I would clone the project so you can mess up endlessly.
Then I would start to reduce the code. "What happens if if just remove this function here?
Also get django debug toolbar:
https://github.com/django-debug-toolbar/django-debug-toolbar
A good terminal debugger is also golden, there are many out there, here is an example:
https://github.com/tomchristie/django-pdb
This allow you to halt the code and even inject and mutate parameters in runtime. Just like GDB in C.
If you use FireFox you can install FireBug on it and when you for example submit ajax form you can see at which url send you request after what you can easily find controller which work with this form data. At chrome this utility embedded by default and call by F12 key.
I'm developing an app (an API) in python and I would like to offer some of its functionality through a web interface (like web services do).
I've been looking at django, but I don't know if really fits well in my idea. I only want to create a web page that invokes to my API methods in order to acomplish the functionality that offers that web page. But, after followed the tutorial, I feel a little confused about the point of django. It seems to me to be more related with an ORM than a classic web application.
Is django a solution so heavy for such a simple development (as I mentioned, make calls to my API through the web)? Do I always have to use a database?
Thanks.
I love django but there is an lot of it to get your head around! If you don't want the database bit, focus on urls.py and views.py that will process your urls and return the info you want as an http response.
eg. urls.py
urlpatterns += patterns('myapp.views',
url(r'^getstuff/$', 'getstuff' ),
)
in views.py
def getstuff(request):
do whatever in python
return HttpResponse(stuff to return)
You don't need to use database in Django projects.
Basically django comes with some standardized architecture that follows MVC pattern (or MVT as sometimes described). This includes models, views, url dispatching, templates, etc.
Probably you need to do following things to accomplish your task:
create url definition in urls.py
to some django view
write
django view that call somehow your
api and displays result as a web
page
you don't need models and database at all but you need to get familliar with views, urls, templates. It might look like a big machinery for your simple case but if you have some time I encourage you to these django basics.
If you are looking for somethin much simpler I heard about webpy project. This might be better option if you need something really simple.
An important question is: Do you want the web services to be provided by a full-featured server like Apache, or are you just looking at the "web server" to be a thread (or equivalent) in your program?
If you want to run Apache, then I'd recommend something like Werkzeug, which will handle most of the WSGI stuff for you. For templating, I've heard good things about Jinja2.
If that is too much, and all you want is a lightweight, simple server (something that, say, just spits out some HTML or XML when asked, and doesn't need any fancy URL handling), you can use the SimpleHTTPServer or CGIHTTPServer modules that ship with Python.
Django is a full-featured, integrated package that provides almost everything you need to write database-backed web applications. While its various components can be used in isolation, if you're only using one thing (the template and view engines, in your case), it is probably overkill.
No need for a framework at all. Raw wsgi isn't hard but a little verbose. So I like to use WebOb
Here's Raw wsgi
def application(environ, start_response):
start_response("200 OK", [])
return ["<html><body><h1>Hello World</h1></body></html>"]
Here's the webob version
from webob.dec import wsgify
from webob import Request
#wsgify
def application(request):
return Response("<html><body><h1>Hello World</h1></body></html>")
That's enough to run under apache mod_wsgi, and there are plenty of libraries that you can use that expect/produce webob Request and Responses. Anything that Turbogears 2 or repoze.bfg uses is fair game at that point.
You definitely don't have to use a database with Django. Whether it fits your needs, only you can tell. There are other Python web frameworks that you can use.