[ python-Bugs-1202946 ] Problem with abs function

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Bugs item #1202946, was opened at 2005-05-16 11:32
Message generated for change (Comment added) made by rhettinger
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Category: Python Interpreter Core
Group: Python 2.4
>Status: Closed
>Resolution: Out of Date
Priority: 5
Submitted By: ric-b (ric-b)
Assigned to: Nobody/Anonymous (nobody)
Summary: Problem with abs function

Initial Comment:
On windows version I get :

>>> abs(-9999999999999999999)

Traceback (most recent call last):
  File "<pyshell#7>", line 1, in -toplevel-
    abs(-9999999999999999999)
OverflowError: long too big to convert

does not handle new longs.


I am using the following work around:

            t = a - b  # calc t = abs(a - b)
            if t < 0 :  
                t *= -1


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>Comment By: Raymond Hettinger (rhettinger)
Date: 2005-05-26 02:12

Message:
Logged In: YES 
user_id=80475

No response from the OP.
Presuming that Terry's explanation is correct.
Please re-open if presented with evidence to the contrary.

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Comment By: Terry J. Reedy (tjreedy)
Date: 2005-05-18 21:10

Message:
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Python 2.2.1 (#34, Apr  9 2002, 19:34:33) [MSC 32 bit (Intel)] on 
win32
Type "help", "copyright", "credits" or "license" for more 
information.
>>> abs(-9999999999999999999)
9999999999999999999L

Ric-b: what windows version? Even older?  If the problem is not 
with current or future (cvs) Python, please close this.

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Comment By: Nick Coghlan (ncoghlan)
Date: 2005-05-18 06:53

Message:
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I tried the OP's example in wxPython's PyShell as well as in
the standard interpreter, and got the same result as Raymond.

However, I was able to provoke a similar looking error by
trying to convert a large long to a float (and the exception
is telling the plain truth - a double precision float can't
handle a number that big):

Py> num = 1.0
Py> lng =
-999999999999999999999999999999999999999999999999999999999999999999999
99999999999999999999999999999999999999999999999999999999999999999999999999999999
99999999999999999999999999999999999999999999999999999999999999999999999999999999
99999999999999999999999999999999999999999999999999999999999999999999999999999999
99999999999999999999999999999999999999999999999999999999999999999999999999999999
999999999999
Py> num += abs(lng)
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
OverflowError: long int too large to convert to float

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Comment By: Raymond Hettinger (rhettinger)
Date: 2005-05-16 12:33

Message:
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That's odd.  It works for me:

Python 2.4.1 (#65, Mar 30 2005, 09:13:57) [MSC v.1310 32 bit
(Intel)] on win32
Type "help", "copyright", "credits" or "license" for more
information.
>>> abs(-9999999999999999999)
9999999999999999999L


----------------------------------------------------------------------

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