class UserProfile(models.Model):
  # This field is required.
  user = models.ForeignKey(User, unique=True, related_name="connector")
  location = models.CharField(max_length=20, blank=True, null=True)

def create_user_profile(sender, instance, created, **kwargs):
  if created:
    UserProfile.objects.create(user=instance)

post_save.connect(create_user_profile, sender=User)

class UserForm(ModelForm):
  class Meta:
    model = User

class UserProfileForm(ModelForm):
  class Meta:
    model = UserProfile

@csrf_protect
def register(request):
  if request.method == 'POST':
    form1 = UserForm(request.POST)
    form2 = UserProfileForm(request.POST)
    if form1.is_valid() and form2.is_valid():
      #create initial entry for user
      username = form1.cleaned_data["username"]
      password = form1.cleaned_data["password"]
      new_user = User.objects.create_user(username, password)
      new_user.save()

      #create entry for UserProfile (extension of new_user object)
      profile = form2.save(commit = False)
      profile.user = new_user
      profile.save()
      return HttpResponseRedirect("/books/")
  else:
    form1 = UserForm()
    form2 = UserProfileForm()
  c = {
    'form1':form1,
    'form2':form2,
  }
  c.update(csrf(request))
  return render_to_response("registration/register.html", c)

<form action="/accounts/register/" method="post">{% csrf_token %}
   <p style="color:red"> {{form.username.errors}}</p>
    {{ form1.as_p }}
    {{ form2.as_p }}
    <input type="submit" value="Create the account">
</form>

@csrf_protect
def register(request):
  if request.method == 'POST':
    form1 = UserForm(request.POST, prefix = "user")
    form2 = UserProfileForm(request.POST, prefix = "profile")
    if form1.is_valid() and form2.is_valid():
      #create initial entry for user
      username = form1.cleaned_data["username"]
      password = form1.cleaned_data["password"]
      new_user = User.objects.create_user(username, password)
      new_user.save()

      #create entry for UserProfile (extension of new_user object)
      profile = form2.save(commit = False)
      profile.user = new_user
      profile.save()
      return HttpResponseRedirect("/books/")
  else:
    form1 = UserForm(prefix = "user")
    form2 = UserProfileForm(prefix = "profile")
  c = {
    'form1':form1,
    'form2':form2,
  }
  c.update(csrf(request))
  return render_to_response("registration/register.html", c)

class UserProfileForm(ModelForm):
  class Meta:
    model = UserProfile
    exclude = ('user',)

class UserProfile(models.Model):
      user = models.ForeignKey(User, unique=True, related_name="connector")
      location = models.CharField(max_length=20, blank=True, null=True)

@csrf_protect
def register(request):
      if request.method == 'POST':
          form1 = UserForm(request.POST)
          form2 = UserProfileForm(request.POST)
          if form1.is_valid() and form2.is_valid():
               #create initial entry for user
               username = form1.cleaned_data["username"]
               password = form1.cleaned_data["password"]
               new_user = User()
               new_user.username = username
               new_user.set_password(password)
               new_user.save()

               profile = UserProfile()
               profile.user = new_user
               profile.save()
               return HttpResponseRedirect("/books/")
      else:
          form1 = UserForm()
          form2 = UserProfileForm()
      c = {
               'form1':form1,
               'form2':form2,
              }
      c.update(csrf(request))
      return render_to_response("registration/register.html", c)