How are POST and GET variables handled in Python?

suppose you're posting a html form with this:

<input type="text" name="username">

If using raw cgi:

import cgi
form = cgi.FieldStorage()
print form["username"]

If using Django, Pylons, Flask or Pyramid:

print request.GET['username'] # for GET form method
print request.POST['username'] # for POST form method

Using Turbogears, Cherrypy:

from cherrypy import request
print request.params['username']

Web.py:

form = web.input()
print form.username

Werkzeug:

print request.form['username']

If using Cherrypy or Turbogears, you can also define your handler function taking a parameter directly:

def index(self, username):
    print username

Google App Engine:

class SomeHandler(webapp2.RequestHandler):
    def post(self):
        name = self.request.get('username') # this will get the value from the field named username
        self.response.write(name) # this will write on the document

So you really will have to choose one of those frameworks.

They are stored in the CGI fieldstorage object.

import cgi
form = cgi.FieldStorage()

print "The user entered %s" % form.getvalue("uservalue")

It somewhat depends on what you use as a CGI framework, but they are available in dictionaries accessible to the program. I'd point you to the docs, but I'm not getting through to python.org right now. But this note on mail.python.org will give you a first pointer. Look at the CGI and URLLIB Python libs for more.

Update

Okay, that link busted. Here's the basic wsgi ref

Python is only a language, to get GET and POST data, you need a web framework or toolkit written in Python. Django is one, as Charlie points out, the cgi and urllib standard modules are others. Also available are Turbogears, Pylons, CherryPy, web.py, mod_python, fastcgi, etc, etc.

In Django, your view functions receive a request argument which has request.GET and request.POST. Other frameworks will do it differently.