runserver must be manually restarted after error in models.py

Question

I'm following the book The Definitive Guide to Django and one thing I've started noticing is that whenever I make a single error in my models file, the server just hangs and is not automatically restarted when the error is fixed.

Here's an example: I save the file with a line like this

email = models.EmailField(blank=Tru)

Which raises the obvious error and stack trace

Validating models...

Unhandled exception in thread started by <bound method Command.inner_run of <django.core.management.commands.runserver.Command object at 0x00000000025B0400>>
Traceback (most recent call last):
  File "C:\Python27\lib\site-packages\django\core\management\commands\runserver.py", line 91, in inner_run
    self.validate(display_num_errors=True)
  File "C:\Python27\lib\site-packages\django\core\management\base.py", line 266, in validate
    num_errors = get_validation_errors(s, app)
  File "C:\Python27\lib\site-packages\django\core\management\validation.py", line 30, in get_validation_errors
    for (app_name, error) in get_app_errors().items():
  File "C:\Python27\lib\site-packages\django\db\models\loading.py", line 158, in get_app_errors
    self._populate()
  File "C:\Python27\lib\site-packages\django\db\models\loading.py", line 64, in _populate
    self.load_app(app_name, True)
  File "C:\Python27\lib\site-packages\django\db\models\loading.py", line 88, in load_app
    models = import_module('.models', app_name)
  File "C:\Python27\lib\site-packages\django\utils\importlib.py", line 35, in import_module
    __import__(name)
  File "C:\....\models.py", line 17, in <module>
    class Author(models.Model):
  File "C:\...\models.py", line 20, in Author
    email = models.EmailField(blank=Tru)
NameError: name 'Tru' is not defined 

Now, if I change Tru to True, the server does not restart. Is this intentional? Or is there something wrong with my application? I've just started learning Django so I have no idea if this is common behaviour.

I'm on Windows, running Python 2.7.3 and Django 1.4.1.

Answer 1

Not just you- I also experience this on occasion.

Although the development server is usually pretty good about restarting after code changes, some particularly egregious errors (especially in your models.py) can sometimes cause it to hang. Just need to terminate it (Ctrl+C), restart it, and continue along your merry way.