How to put infinity and minus infinity in Django FloatField?

Question

I am trying to put infinity in a FloatField, but that doesn't seem to work. How do I solve this?

f = DjangoModel(float_value=float('inf')) #ok
f.save() #crashes

Results in:

Traceback (most recent call last):
...
ProgrammingError: column "inf" does not exist
LINE 1: ... "float_value") VALUES (inf)

I'm using Django 1.0.2 with PostgreSQL 8.3

Answer 1

It should be 'infinity' shouldn't it? However, I don't know if that can be stored in a float field. float('infinity') returns inf, and that would be a char field.

Edit: Unfortunately, it is hard to say what C library Django uses without digging deep. I'd say figure out what the value stored in the float field actually is, or at least determine what is being returned. If it is indeed "inf", then that cannot be stored properly in a float field.

Answer 2

It seems like Djangos ORM doesn't have any special handling for this. Pythons representaton of the values are inf and -inf, while PostgrSQL wants 'Infinity' and '-Infinity'. Obviously Djangos ORM doesn't handle that conversion.

So you need to fix the ORM, I guess. And then think about the fact that other SQL databases may very well want other formats, or won't handle infinities at all.