Django: Best way to implement "status" field in modules

Question

I have a field in my module that is used to hold the status of the object. So far I have used:

ORDER_STATUS = ((0, 'Started'), (1, 'Done'), (2, 'Error'))
status = models.SmallIntegerField(choices=ORDER_STATUS)

Its easy to convert one way:

def status_str(self): return ORDER_STATUS[self.status][1]

The problem is when updating. I find myself having code like this:

order.status = 2 # Error Status

Which is quite awful and gets really hard to synchronize. I guess a solution would be something similar to C's enum{}. Or perhaps there is a whole different way to tackle this problem ?

Thanks

Answer 1

you can try enum package: http://pypi.python.org/pypi/enum/

Answer 2

Maybe this question helps you: Set Django IntegerField by choices=… name.
I quote from the accepted answer (with adjustments ;)):
Put this into your class (STATUS_CHOICES will be the list that is handed to the choices option of the field):

PENDING = 0
DONE = 1
STATUS_CHOICES = (
    (PENDNING, 'Pending'),
    (DONE, 'Done'),
)

Then you can do order.status = Order.DONE.

---

Note that you don't have to implement an own method to retrieve the (readable) value, Django provides the method get_status_display itself.

Answer 3

You don't need your status_str method - Django automatically provides a get_status_display() which does exactly the same thing.

To reverse, you could use this:

def set_order_status(self, val):
    status_dict = dict(ORDER_STATUS)
    self.status = status_dict[val][0]

Now you can do:

order.set_order_status('Done')

Answer 4

what I usually do for this situation is:

models.py

from static import ORDER_STATUS    
status = models.SmallPositiveIntegerField(choices=ORDER_STATUS)

static.py

ORDER_STATUS = ((0, 'Started'), (1, 'Done'), (2, 'Error'))
ORDER_STATUS_DICT = dict((v, k) for k, v in ORDER_STATUS)

Now you can do:

from static import ORDER_STATUS_DICT
order.status = ORDER_STATUS_DICT['Error']

Answer 5

Maybe stick a method on the model, like:

def status_code(self, text):
    return [n for (n, t) in self.ORDER_STATUS if t == text][0]

Then you’d do:

order.status = order.status_code('Error')