class AuthorLogin(forms.Form):
    username = forms.CharField(label='Your name', max_length=100)
    password = forms.CharField(
                           label='Your password',
                           max_length=100,
                           widget=forms.PasswordInput)

    def clean(self):
        username = self.cleaned_data.get('username')
        password = self.cleaned_data.get('password')
        user = authenticate(username=username, password=password)
        if not user or not user.is_active:
            raise forms.ValidationError('Invalid username or password', code='invalid')
        return self.cleaned_data

    def login(self, request):
        username = self.cleaned_data.get('username')
        password = self.cleaned_data.get('password')
        user = authenticate(username=username, password=password)
        return user

def author_login(request):
    form = AuthorLogin(request.POST or None)
    if request.POST and form.is_valid():
        user = form.login(request)
        if user is not None:
            login(request, user)
            return redirect('microblog:index')

    return render(request, 'microblog/author_login.html', {'form': form})

app_name = 'microblog'
urlpatterns = [
    url(r'^$', views.index, name='index'),
    url(r'^login/', views.author_login, name='author_login'),
    url(r'^logout/', views.author_logout, name='author_logout'),
]

{% extends "base.html" %}

{% block content %}
{% if form.non_field_errors %}
  <ul>
    {% for error in form.non_field_errors %}
     <li>{{ error }}</li>
    {% endfor %}
  </ul>
{% endif %}
<form action="" method="post">
  {% csrf_token %}
  {{ form.as_p }}
  <input type="submit" value="Login" />
</form>
{% endblock %}