Question

I’ve got a Django-based site that allows users to register (but requires an admin to approve the account before they can view certain parts of the site). I’m basing it off of django.contrib.auth. I require users to register with an email address from a certain domain name, so I’ve overridden the UserCreationForm‘s save() and clean_email() methods.

My registration page uses the following view. I’m interested in hearing about how I might improve this view—code improvements or process improvements (or anything else, really).

def register(request):     if request.method == 'POST':         form = UserCreationForm(request.POST)          if form.is_valid():             message = None              form.save()              username = form.cleaned_data['username']             password = form.cleaned_data['password1']              user = authenticate(username=username, password=password)              first_name = form.cleaned_data['first_name']             last_name = form.cleaned_data['last_name']             email = user.email              # If valid new user account             if (user is not None) and (user.is_active):                 login(request, user)                 message = '<strong>Congratulations!</strong> You have been registered.'                  # Send emails                 try:                     # Admin email                     pk = None                     try: pk = User.objects.filter(username=username)[0].pk                     except: pass                      admin_email_template = loader.get_template('accounts/email_notify_admin_of_registration.txt')                     admin_email_context = Context({                         'first_name': first_name,                         'last_name': last_name,                         'username': username,                         'email': email,                         'pk': pk,                     })                     admin_email_body = admin_email_template.render(admin_email_context)                     mail_admins('New User Registration', admin_email_body)                      # User email                     user_email_template = loader.get_template('accounts/email_registration_success.txt')                     user_email_context = Context({                         'first_name': form.cleaned_data['first_name'],                         'username': username,                         'password': password,                     })                     user_email_body = user_email_template.render(user_email_context)                     user.email_user('Successfully Registered at example.com', user_email_body)                 except:                     message = 'There was an error sending you the confirmation email. You should still be able to login normally.'             else:                 message = 'There was an error automatically logging you in. Try <a href=\'/login/\'>logging in</a> manually.'              # Display success page             return render_to_response('accounts/register_success.html', {                     'username': username,                     'message': message,                 },                 context_instance=RequestContext(request)             )     else: # If not POST         form = UserCreationForm()      return render_to_response('accounts/register.html', {             'form': form,         },         context_instance=RequestContext(request)     ) 

Answer 1

You don’t even need this code, but I think the style:

pk = None try: pk = User.objects.filter(username=username)[0].pk except: pass 

is more naturally written like:

try:     user = User.objects.get(username=username) except User.DoesNotExist:     user = None 

and then in your admin notify template use {{ user.id }} instead of {{ pk }}.

But, like I said, you don’t need that code at all because you already have a user object from your call to authenticate().

Generally in Python, it’s considered poor practice to have the exception handler in a try/except block be empty. In other words, always capture a specific exception such as User.DoesNotExist for this case.

It’s also poor practice to have many lines inside the try part of the try/except block. It is better form to code this way:

try:     ... a line of code that can generate exceptions to be handled ... except SomeException:     ... handle this particular exception ... else:     ... the rest of the code to execute if there were no exceptions ... 

A final, minor, recommendation is to not send the email directly in your view because this won’t scale if your site starts to see heavy registration requests. It is better add in the django-mailer app to offload the work into a queue handled by another process.