title: (Django) Cannot assign "u'1'": "StaffProfile.user" must be a "User" instance
body: <p>I have a model like below:</p>
  
  <pre><code>class StaffProfile(models.Model):
      user = models.ForeignKey(User)
      maas = models.FloatField()
      maas_gunu = models.CharField(max_length=5)
  </code></pre>
  
  <p>When I try to insert data with a code like below:</p>
  
  <pre><code>staffprofilesay = StaffProfile.objects.filter(user = user_id).count()
  
       if staffprofilesay &gt; 0:
          staffprofile = StaffProfile.objects.get(user = user_id)
       else:    
          staffprofile = StaffProfile()
  
       staffprofile.user = user_id
       staffprofile.maas = calisan_formu.cleaned_data["maas"]
       staffprofile.maas_gunu = calisan_formu.cleaned_data["maas_gunu"]
       staffprofile.save()
  </code></pre>
  
  <p>I get an error like this:</p>
  
  <pre><code>Cannot assign "u'1'": "StaffProfile.user" must be a "User" instance.
  </code></pre>
  
  <p>What am I supposed to do?</p>
  
  <p>PS: I'm using Django's User model</p>