from django.contrib.auth.models import User
from django.db import models

class Profile(models.Model):
    user = models.OneToOneField(User)
    display_name = models.CharField(max_length=145, blank=True, null=True)
    bio = models.CharField(max_length=1000, blank=True, null=True)

class Module(models.Model):
    name = models.CharField(max_length=45)
    semester = models.CharField(max_length=40)
    prof = models.ForeignKey('Profile', null=True, blank=True)

class ModuleForm(ModelForm):
    class Meta:
        model = Module
        fields = ['name',  'semester']

prof = Profile.objects.get(user=request.user)
if request.method == 'POST':
    mtb = request.POST._mutable
    request.POST._mutable = True
    request.POST['prof'] = str(prof.id)
    request.POST._mutable = mtb
    moduleform = ModuleForm(request.POST)
    moduleform.save()

moduleform.save(commit=False)
moduleform.prof = prof
moduleform.save()