Peculiar boundary cases:
>>> 2.0**31-1.0
2147483647.0
>>> int(2147483647.0)
2147483647L
>>> int(2147483647L )
2147483647
>>>
>>> -2.0**31
-2147483648.0
>>> int(-2147483648.0)
-2147483648L
>>> int(-2147483648L )
-2147483648
some kind of one-off error? I.e., just inside extremes works:
>>> [int(x) for x in (-2.0**31, -2.0**31+1.0, 2.0**31-2.0, 2.0**31-1.0)]
[-2147483648L, -2147483647, 2147483646, 2147483647L]
But those longs at the extremes can be converted successfully, so int(int(x))
works ;-/
>>> [int(int(x)) for x in (-2.0**31, -2.0**31+1.0, 2.0**31-2.0, 2.0**31-1.0)]
[-2147483648, -2147483647, 2147483646, 2147483647]
ISTM this is a buglet, or at least a wartlet for a 32-bit system ;-)
Almost forgot:
Python 2.4b1 (#56, Nov 3 2004, 01:47:27)
[GCC 3.2.3 (mingw special 20030504-1)] on win32
but same thing on 2.3.2:
Python 2.3.2 (#49, Oct 2 2003, 20:02:00) [MSC v.1200 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> [int(x) for x in (-2.0**31, -2.0**31+1.0, 2.0**31-2.0, 2.0**31-1.0)]
[-2147483648L, -2147483647, 2147483646, 2147483647L]
>>> [int(int(x)) for x in (-2.0**31, -2.0**31+1.0, 2.0**31-2.0, 2.0**31-1.0)]
[-2147483648, -2147483647, 2147483646, 2147483647]
Hm, ... except for the thought that CPUs with 64-bit integers might truncate
maxint
when converting to float, I might say maybe these reprs should be tested
for equality in the system tests?
>>> import sys
>>> repr(int(float(sys.maxint))), repr(sys.maxint)
('2147483647L', '2147483647')
>>> repr(int(float(-sys.maxint-1))), repr(-sys.maxint-1)
('-2147483648L', '-2147483648')
or maybe at least check for equality of these?:
>>> type(int(float(sys.maxint))), type(sys.maxint)
(<type 'long'>, <type 'int'>)
>>> type(int(float(-sys.maxint-1))), type(-sys.maxint-1)
(<type 'long'>, <type 'int'>)
Regards,
Bengt Richter
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