[patch] forms.FloatField is incompatible with models.FloatField

[adurdin@…]

This relates to #2365; models.FloatField uses decimal.Decimal objects, but forms.FloatField uses float() to convert its data to python objects. This causes a loss of accuracy when using high-precision decimals, e.g. models.FloatField(max_digits=30, decimal_places=18): 0.7 entered into the field in the admin interface will be saved as 0.699999999999999956.

[adurdin@…]

Patch

[anonymous]

A note for when we get to this: If we wanted to go down this route, we would need to start shipping our own copy of the decimal module with Django. It is not in the standard Python library prior to Python 2.4 (and Django is implemented to work with Python 2.3).

[adurdin@…]

Would there be any problem with limiting the decimal dependency to the DecimalField-related bits? That should be straightforward enough.

[adurdin@…]

Closing this -- see #2365 instead, as they are very closely related.