[Bf-committers] Precision and default range of IntProperty

IRIE Shinsuke irieshinsuke at yahoo.co.jp
Fri Oct 4 16:45:08 CEST 2013

Hi devs,

In Python3, "int" type number has variable precision, but IntProperty
provides a fixed precision integer.  So, if a Python script saves a
very large number in the intger property, the value may overflow and
cause unexpected results.  Indeed, an error caused by such overflow
was reported in the tracker:


Why doesn't integer property use variable precision?  Intentional?

One more thing,

The description of IntProperty says "... min=-sys.maxint, max=sys.maxint, ...".
Here, sys.maxint not existing in Python3 can be substituted with
sys.maxsize.  However, IntProperty actually uses INT_MIN and INT_MAX
for the default range, and sys.maxsize is not same as INT_MAX.

On Ubuntu (64bit or 32bit),

sys.maxsize = 9223372036854775807 or 2147483647

INT_MAX = 2147483647
LONG_MAX = 9223372036854775807L or 2147483647L
LLONG_MAX = 9223372036854775807LL

We should correct the description or change the default range.


IRIE Shinsuke

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