from django.db import models

# Create your models here.
class Student(models.Model):
    sfid = models.IntegerField(primary_key=True)
    name = models.CharField(max_length=200)
    group = models.ForeignKey(Groupname, on_delete=models.CASCADE)

    # def __str__(self):
    #     return self.name

class Groupname(models.Model):
    group_name = models.CharField(max_length=200)

    # def __str__(self):
    #     return self.group_name

Traceback (most recent call last):
  File "manage.py", line 22, in <module>
    execute_from_command_line(sys.argv)
  File "/usr/install/python3/lib/python3.5/site-packages/django/core/management/__init__.py", line 367, in execute_from_command_line
    utility.execute()
  File "/usr/install/python3/lib/python3.5/site-packages/django/core/management/__init__.py", line 341, in execute
    django.setup()
  File "/usr/install/python3/lib/python3.5/site-packages/django/__init__.py", line 27, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/usr/install/python3/lib/python3.5/site-packages/django/apps/registry.py", line 108, in populate
    app_config.import_models(all_models)
  File "/usr/install/python3/lib/python3.5/site-packages/django/apps/config.py", line 199, in import_models
    self.models_module = import_module(models_module_name)
  File "/usr/install/python3/lib/python3.5/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 986, in _gcd_import
  File "<frozen importlib._bootstrap>", line 969, in _find_and_load
  File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 665, in exec_module
  File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
  File "/root/django_projects/mysite/polls/models.py", line 4, in <module>
    class Student(models.Model):
  File "/root/django_projects/mysite/polls/models.py", line 7, in Student
    group = models.ForeignKey(Groupname,on_delete=models.CASCADE)
NameError: name 'Groupname' is not defined