[ python-Bugs-1571620 ] round() producing -0.0

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Bugs item #1571620, was opened at 2006-10-05 13:14
Message generated for change (Comment added) made by rhettinger
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Category: None
Group: None
>Status: Closed
>Resolution: Invalid
Priority: 5
Submitted By: Ron Frye (rrfsf01)
Assigned to: Nobody/Anonymous (nobody)
Summary: round() producing -0.0

Initial Comment:
python 2.2 on AIX 4.3 produces:

>>> round(-0.0001, 1)
0.0
>>>


python 2.4.1 on Linux Red Hat Enterprise 3 produces:

>>> round(-0.0001, 1)
-0.0
>>> round(-0.0001, 1) == 0.0
True
>>>


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>Comment By: Raymond Hettinger (rhettinger)
Date: 2006-10-05 13:39

Message:
Logged In: YES 
user_id=80475

Since 0.0 == -0.0, the result in not wrong.  The underlying
C math library dictates whether signed zeroes are used, so
round(-0.0001, 1) returns the same result as 
math.ceil(-0.0001 * 10).

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