[Python-bugs-list] [ python-Bugs-426345 ] Problem with addition

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Bugs item #426345, was updated on 2001-05-22 09:58
You can respond by visiting: 
http://sourceforge.net/tracker/?func=detail&atid=105470&aid=426345&group_id=5470

Category: None
>Group: Not a Bug
>Status: Closed
>Resolution: Invalid
Priority: 5
Submitted By: Nobody/Anonymous (nobody)
Assigned to: Nobody/Anonymous (nobody)
Summary: Problem with addition

Initial Comment:
There seems to be a problem with addition in the 
python interactive mode.  This is what I did:

"""

[administrator@RGELPC265 delacruz]$ python
Python 2.1 (#1, Apr 17 2001, 09:45:01)
[GCC 2.95.3-2 (cygwin special)] on cygwin_nt-4.01
Type "copyright", "credits" or "license" for more 
information.
>>> 3.76 + 4.72
8.4800000000000004

"""

Here are my specs:

Python Release:  Python 2.1 (#1, Apr 17 2001, 09:45:01)
Platform:  Windows 2000
Shell:  cygwin


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Comment By: Tim Peters (tim_one)
Date: 2001-05-22 12:43

Message:
Logged In: YES 
user_id=31435

This is not a bug.

Binary floating point cannot represent decimal fractions exactly,
so some rounding always occurs (even in Python 1.5.2).

What changed is that Python 2.0 shows more precision than before
in certain circumstances (repr() and the interactive prompt). 

You can use str() or print to get the old, rounded output: 

>>> print 0.1+0.1
0.2
>>>

Follow the link for a detailed example:

http://www.python.org/cgi-bin/moinmoin/RepresentationError


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You can respond by visiting: 
http://sourceforge.net/tracker/?func=detail&atid=105470&aid=426345&group_id=5470