title: Form required field in django model forms
body: <p>i have a model form however I'm struggling to set one field as required without changing the model itself. Is there a way of making the location field mandatory without changing models.py when the user submits the form?</p>
  
  <p>modelys.py </p>
  
  <pre><code>class Profile(models.Model):
      user = models.OneToOneField(User)
      location = models.CharField(max_length=120, null=True, blank=True)
      picture = models.ImageField(upload_to=upload_location, null=True, blank=True)
      gender = models.CharField(max_length=120, null=True, choices=GENDER, blank=True)
      bio = models.CharField(max_length=1000, null=True, blank=True)
      home_university = models.CharField(max_length=50, null=True, blank=True)
  </code></pre>
  
  <p>my forms.py</p>
  
  <pre><code>class ProfileForm(forms.ModelForm):
      class Meta:
          model = Profile
          fields = [
              "location",
              "picture",
              "bio",
              "gender",
              "home_university",
              ]
  </code></pre>
  
  <p>and my views.py </p>
  
  <pre><code>@login_required
  def profile_complete(request):
      profile, created = Profile.objects.get_or_create(user=request.user)
      form = ProfileForm(request.POST or None, request.FILES or None, instance=profile)
      if form.is_valid():
          instance = form.save(commit=False)
          instance.user = request.user
          instance.save()
          return redirect("home")
      context = {
          "form": form,
  
                  }
      return render(request, "profiles/profile_complete.html", context)
  </code></pre>