This `LOOKUP_SEP` is in the 1.4 series as well:

> https://github.com/django/django/blob/1.4/django/db/models/sql/constants.py#L15
> https://github.com/django/django/blob/1.4.1/django/db/models/sql/constants.py#L15
> https://github.com/django/django/blob/1.4.2/django/db/models/sql/constants.py#L15
> https://github.com/django/django/blob/1.4.3/django/db/models/sql/constants.py#L15
> https://github.com/django/django/blob/1.4.4/django/db/models/sql/constants.py#L15
> https://github.com/django/django/blob/1.4.5/django/db/models/sql/constants.py#L15

No need for the try except, just import from the sql constants.

```python
from django.db.models.sql.constants import LOOKUP_SEP
```