I am wondering how to go about implementing a web application with Python.
For example, the html pages would link to python code that would give it increased functionality and allow it to write to a database.
Kind of like how Reddit does it.
If you're looking for server side programming with databases and html templates etc, I think Django is great, along with Pyramid. However, I use Flask ( http://flask.pocoo.org/ ) for this since it is easy to use, learn and deploy even though it may not have as much support as the before mentioned 2 framework since it's just a microframework, using the Jinja2 templating engine, including a development test server with it's own debugger.
On the other hand, if you're going for client-side programming (i.e. in browser implementation ) You can look up .NET Ironpython or even Brython which uses python like javascript.
You might want to check out mod_wsgi or mod_python.
What Is mod_wsgi?
The aim of mod_wsgi is to implement a simple to use
Apache module which can host any Python application which supports the
Python WSGI interface. The module would be suitable for use in hosting
high performance production web sites, as well as your average self
managed personal sites running on web hosting services.
-
Current State of Mod_Python
Currently mod_python is not under active development. This does not
mean that it is "dead" as some people have claimed. It smiply means
that the code and the project are mature enough when very little is
required to maintain it.
This is a good article from the Python website:
http://docs.python.org/howto/webservers.html
Plain CGI is a good starting point to learn about server side scripting, but it is an outdated technology and gets difficult to maintain after certain level of complexity. I would think it is no longer used in industrial-grade web server anymore. Plus you have to setup a web server and then install some module to interpret python script (like Apache with mod_python) just to get started.
I had some experience with Django (https://www.djangoproject.com/) and found it fairly easy to get started with since they come with development test server. All you need to have is a Python interpreter + Django and you can get up-and-running quickly and worry about the deployment setup later. They have pretty good documentation for beginner as well.
We have never used Python for a web site without a framework. In our case that is Django. In other words, we do not use Python for our web sites the way Perl can be used, just having Apache run a Perl script.
The recommendations you have received about Django are sound. If you go the Django route, Graham Dumpleton and the modwsgi Google group were very helpful to me. I could
not have gotten mod_wsgi deployed on Red Hat Enterprise 5 64-bit without Graham's help.
Whether you choose Django or "straight" Python, you will need to become familiar with mod_wsgi.
Good luck in quantum time, which means by now, I hope this all worked out for you.
Related
I'm building an application on AWS and well, this world is new to me.
I expose the problem
I have experience with Apache / PHP, Apache is the one who helps me serve HTTP requests and PHP is the language of Backend.
The backend language that I am using in this new project is Python, but my question is, what is the technology that helps me serve the requests?
Can I install Apache / Python, or what would be the perfect duo?
I know this can have many variants depending on each experience and needs of the project, but honestly I am lost in what to install and what not.
Thanks for your guidance
Your best course of action if just learning how to do web programming in Python is to not worry about how you host it. Start out with one of the major Python web frameworks and work through their tutorials. The best options are:
Flask - http://flask.pocoo.org/
Django - https://www.djangoproject.com/
They will explain the basics of building your web application. They use a development server to host your application. Only once you understand programming basics, then worry about a production grade web server.
I would recommend to look at uWSGI:
https://uwsgi-docs.readthedocs.io/en/latest/WebServers.html
mod_wsgi for Apache:
https://modwsgi.readthedocs.io/en/develop/
For simple pages you still have CGI:
https://docs.python.org/3.6/library/cgi.html
There exists also mod_python for Apache, but it isn't modern way to embed Python interpreter within the webserver (don't use it, here only for information purposes!).
http://modpython.org/
I have a couple of Python 2.7 scripts I need to have them run from a webpage. I've never done this before, although I'm comfortable coding in Python and well versed in Linux, Apache, Nginx.
I see many different frameworks like the old CGI, WSGI, Django, etc.
I need some recommendations for a framework that would require not much changes on my Python code for it to run on a webpage.
It seems CGI would be fairly easy for me, but since there are many newer frameworks, I need some advices.
Thanks!
Flask is probably the most straightforward Python web framework to use. It touts itself as a micro framework, and is very, very fast to get up and running with.
If you have a relatively straightforward set of requirements, I'd highly recommend giving it a look over. You can find the "hello" world example on the project's homepage here: http://flask.pocoo.org/
Depending on your project's requirements (does it need to be highly available/resilient?), you may even be able to get by using Flask's built-in development webserver along with a process control system such as supervisord. I wouldn't recommend this for heavy or production workloads, but for something running out of production this set up would work just fine for you.
If you're looking for client side browser frameworks in Python, there are skulpt and brython.
When I was looking for a similar framework, I decided to learn leave python for a javascript framework (particularly AngularJS and Node JS) for a client side language. I personally felt that the size of community and learning resources available in those two areas were more robust, and provided greater opportunity to master the framework.
I have been looking at setting up a web server to use Python and I have installed Apache 2.2.22 on Debian 7 Wheezy with mod_wsgi. I have gotten the initial page up and going and the Apache will display the contents of the wsgi file that I have in my directory.
However, I have been researching on how to deploy a Python application and I have to admin, I find some of it a little confusing. I am coming from a background in PHP where it is literally install what you need and you are up and running and PHP is processing the way it should be.
Is this the same with Python? I can't seem to get anything to process outside of the wsgi file that I have setup. I can't import anything from other files without the server throwing a "500" error. I have looked on Google and Bing to try to find an answer to this, but I can't seem to find anything, or don't know that what I have been looking at is the answer.
I really appreciate any help that you guys can offer.
Thanks in advance! (If I need to post any coding, I can do that, I just don't know what you guys would need, if anything, as far as coding examples for this...)
Python is different from PHP in that PHP executes your entire program separately for each hit to your website, whereas Python runs "worker processes" that stay resident in memory.
You need some sort of web framework to do this work for you (you could write your own, but using someone else's framework makes it much easier). Flask is an example of a light one; Django is an example of a very heavy one. Pick one and follow that framework's instructions, or look for tutorials for that framework. Since the frameworks differ, most practical documentation on handling web services with Python are focused around a framework instead of just around the language itself.
Nearly any python web framework will have a development server that you can run locally, so you don't need to worry about deploying yet. When you are ready to deploy, Apache will work, although it's usually easier and better to use Gunicorn or another python-specific webserver, and then if you need more webserver functionality, set up nginx or Apache as a reverse proxy. Apache is a very heavy application to use for nothing but wsgi functionality. You also have the option of deploying to a PaaS service like Heroku (free for development work, costs money for production applications) which will handle a lot of sysadmin work for you.
As an aside, if you're not using virtualenv to set up your Python environment, you should look into it. It will make it much easier to keep track of what you have installed, to install new packages, and to isolate an environment so you can work on multiple projects on the same computer.
I don’t want to burden you all with the details, but basically I’m a 2nd year compsci student with no Web dev experience.
Basically I want to create a small “web app” that takes in input from a html form, have a python script perform some calculations, and re-display those results in your browser.
As of right now, I have the form and script built. However, when I try to test the form, instead of running the script, my browser tries to download it. To my understanding, this is a cgi script problem, and that I must create a web server in order to test this script.
And heres were I’m stuck. I know little to nothing about web servers and how to set them up. On top of that I’ve heard that GCI scripting is a thing of the past, and requires major overhead in order to run properly.
This leads to my questions. How do I go about completing my app and testing my cgi script? Do I install apache and mess around with it or should I be looking into something like google app engine? Are there other ways to complete this task without cgi scripts? Where do frameworks like Django fit into this?
Django, while being nice, all-encompassing and well-supported, is sometimes too much for a small web application. Django wants you to play by its rules from the beginning, you'll have to avoid things like the database and admin panels if you don't need them. It's also easier, with Django, to follow its project layout, even when it's too complex for a simple app.
The so-called micro frameworks might suit you better for your small app. They are built upon the opposite principle: use the bare minimum of features now, add more as you need them.
Flask is based on Werkzeug WSGI library and Jinja2 templating (the latter is switchable), is extensively documented (with notes concerning virtualenv and stuff) and well-suited for small and larger apps alike. It comes bundled with an auto-reloading dev server (no need for Apache on your dev machine) and Werkzeug-powered interactive debugger. There are extensions for things like HTML forms and database ORM.
Bottle is as small as a microframework can get, consisting of 1 (one) file, dev server included. Drop it into your project folder and start hacking. The built-in SimpleTemplate templating engine is switchable, but the dev server is flakier in comparison to Flask's. The documentation is less complete, and, in my opinion, the whole thing is less polished and convenient as Flask.
In both cases, you use dev server locally, and then deploy using WSGI, the server interface for Python web apps which both frameworks support. There are many ways to deploy a WSGI app, Apache mod_wsgi being one of the popular ones.
I'd totally go with Flask unless one dependency (Bottle) is better than three (Flask, Jinja2 and Werkzeug).
(There are many other frameworks as well, so wait for their users to come and tell about them. I'd suggest to avoid web.py: it works, but is full of magic, and is inelegant compared to Flask or Bottle.)
One way of getting to working webapp quickly is by first understanding, and then modifying, something like the App Engine "guestbook" example. This has the benefit that much of the otherwise necessary tedium of running a web server and setting up a database server (assuming you need persistence) is done for you. App Engine also provides a fairly flexible development environment. It's certainly not the only way to go, and I'll admit to bias in recommending it, but it's fairly low friction.
GCI scripting is hardly a thing of the past, though it's not what the cool kids are doing. CGI has the benefit, and the curse, of exposing more of the raw plumbing. It forces you to understand a lot about primitive (in the low-level sense) web architecture, but it's also a bit of a large bite to chew on if you have an immediate problem to solve that can solved by simpler means.
It appears most python web development seems to be done by frameworks these days. There are a couple reasons for this:
a plethora of mature tools. Django has built in user auth, built in database management, built in sessions, built in just about everything ORM which lets you seamlessly supports a couple databases.
Built in webservers. The larger python frameworks like django and pylons have built in webservers. Django has a very simple webserver python manage.py startserver (that simple) That makes it extremely easy to create and debug applications. It is single threaded so dropping a debugger into it is painless
Huge communities. If you have a django question it will be answered very quickly the so community is huge.
The django tutorial will introduce you to all the major aspects of development. It is only 4 pages and you will be able to get your app going a lot simpler than having to read, learn and fiddle with an apache setup.
https://docs.djangoproject.com/en/dev/intro/tutorial01/
Although django for right now might be overkill if your app is just going to be 1 form and a script to process it. Because of its seamless testing framework it is quite easy to grow any project. I have never used flask or bottle or the other microframeworks, but I would keep in mind where your project will be in the future.
As for where django fits into this, it is a full stack framework encompassing presentation (templates), data management (server orm), authentication, middleware, forms ... everything necessary to create a completely inclusive web application. Django and almost all other python frameworks implement the wsgi standard. It is an interface that allows for interoperation between webservers. http://en.wikipedia.org/wiki/Web_Server_Gateway_Interface it is pretty dry and you will never have to interface it directly. That is what these frameworks do under the hood.
Why setup and maintain your own webserver if you can use app engine. It has an excellent SDK for testing your code. Here is an example https://developers.google.com/appengine/docs/python/gettingstarted/handlingforms
And Django you will find here : https://developers.google.com/appengine/docs/python/gettingstarted/templates
I prefer to use Jinja for templating.
Django comes with its own server, but in your case i would recommend apache and mod_python since it seems to be a rather simple site you're building.
Setting up Apache is a breeze and a simple search on the web should give you all you need.
You can find more information on mod_python here read up a little bit on it and then google after a tutorial that fits your needs.
I have a python program that I would like to present as a simple web application. The program currently uses sqlite for storage. I also need to distribute the whole thing to colleagues so having something standalone and easy to start would be ideal ( no install if possible). This web app is meant to be used locally , not by multiple users over a network.
Is there a suitable python framework that might fit my needs? I looked at Django so far but it seems a bit heavy handed for what I need.
Thanks for any suggestions.
I have never tried it myself, but you could try Bottle:
Bottle is a fast, simple and lightweight WSGI micro web-framework for
Python. It is distributed as a single file module and has no
dependencies other than the Python Standard Library.
try http://docs.python.org/library/simplehttpserver.html
As web frameworks are not part of the standard lib, you will have to install something in every case. I would propse to look at http://flask.pocoo.org/. It has a build in WSGI server.
Lots of choices for Python web frameworks! Another is web2py which is designed to work out of the box and allows, but doesn't require, through-the-web development. It is mature and has a strong community and is well-documented.
Tornado as a framework may be a lot more than what you're looking for. However it will meet the requirement of being a completely python based web server. http://tornadoweb.org
I generally just download the source, drop it in /tornado/ of my project and do includes there from the app.
I don't think that any web framework is specifically oriented for the use case you're talking about; They all assume they are running on a server and there's a browser on a remote machine that is accessing them.
A better approach is to think about the HTTP server you'll be using. It's probably preferable to use a server that's as easy to pack and ship as the rest of the python code you'll be using. Now most frameworks provide a 'development' server that's easy to invoke from the command line, but most of them are intended to be "easy for the developer" which often means they are restricted to a single thread. This is bad for deployment because single threaded servers will always feel a bit sluggish.
CherryPy stands out in contrast, by providing a full featured, embedded server that's easy to configure for many use cases, and is available by default with the rest of the framework. There are probably others, but I haven't used 'em.