# Set a session value:
request.session["fav_color"] = "blue"

# Get a session value -- this could be called in a different view,
# or many requests later (or both):
fav_color = request.session["fav_color"]

# Clear an item from the session:
del request.session["fav_color"]

# Check if the session has a given key:
if "fav_color" in request.session:
 ...

request.session['_fav_color'] = 'blue' # Don't do this!

request.session = some_other_object # Don't do this!

request.session.foo = 'bar' # Don't do this!

def post_comment(request):
 if request.method != 'POST':
  raise Http404('Only POSTs are allowed')

 if 'comment' not in request.POST:
  raise Http404('Comment not submitted')

 if request.session.get('has_commented', False):
  return HttpResponse("You've already commented.")

 c = comments.Comment(comment=request.POST['comment'])
 c.save()
 request.session['has_commented'] = True
 return HttpResponse('Thanks for your comment!')

def login(request):
 if request.method != 'POST':
  raise Http404('Only POSTs are allowed')
 try:
  m = Member.objects.get(username=request.POST['username'])
  if m.password == request.POST['password']:
   request.session['member_id'] = m.id
   return HttpResponseRedirect('/you-are-logged-in/')
 except Member.DoesNotExist:
  return HttpResponse("Your username and password didn't match.")

def logout(request):
 try:
  del request.session['member_id']
 except KeyError:
  pass
 return HttpResponse("You're logged out.")

def login(request):

 # If we submitted the form...
 if request.method == 'POST':

  # Check that the test cookie worked (we set it below):
  if request.session.test_cookie_worked():

   # The test cookie worked, so delete it.
   request.session.delete_test_cookie()

   # In practice, we'd need some logic to check username/password
   # here, but since this is an example...
   return HttpResponse("You're logged in.")

  # The test cookie failed, so display an error message. If this
  # were a real site, we'd want to display a friendlier message.
  else:
   return HttpResponse("Please enable cookies and try again.")

 # If we didn't post, send the test cookie along with the login form.
 request.session.set_test_cookie()
 return render_to_response('foo/login_form.html')