>>> from django.contrib import auth
>>> user = auth.authenticate(username='john', password='secret')
>>> if user is not None:
...   print "Correct!"
... else:
...   print "Invalid password."

from django.contrib import auth

def login_view(request):
  username = request.POST.get('username', '')
  password = request.POST.get('password', '')
  user = auth.authenticate(username=username, password=password)
  if user is not None and user.is_active:
    # Correct password, and the user is marked "active"
    auth.login(request, user)
    # Redirect to a success page.
    return HttpResponseRedirect("/account/loggedin/")
  else:
    # Show an error page
    return HttpResponseRedirect("/account/invalid/")

from django.contrib import auth

def logout_view(request):
  auth.logout(request)
  # Redirect to a success page.
  return HttpResponseRedirect("/account/loggedout/")

from django.contrib.auth.views import login, logout

urlpatterns = patterns('',
  # existing patterns here...
  (r'^accounts/login/$', login),
  (r'^accounts/logout/$', logout),
)

{% extends "base.html" %}

{% block content %}

 {% if form.errors %}
  <p class="error">Sorry, that's not a valid username or password</p>
 {% endif %}

 <form action="" method="post">
  <label for="username">User name:</label>
  <input type="text" name="username" value="" id="username">
  <label for="password">Password:</label>
  <input type="password" name="password" value="" id="password">

  <input type="submit" value="login" />
  <input type="hidden" name="next" value="{{ next|escape }}" />
 </form>

{% endblock %}