a print bug?

[Duncan Booth]

Summercoolness at gmail.com wrote:

> 
> Sybren Stuvel wrote:
>> It has nothing to do with the print command, and everything with
>> floating point precision. See http://docs.python.org/tut/node16.html
> 
> 
> how about the discrepancy between
> 
>>>> print 1.2345
> 
> 1.2345
> 
>>>> print "%10.3f" % 1.2345    # seems like a bug
> 
>      1.234
> 
> the first one, print knows enough to recognize and print it as 1.2345.
> however, in the second line, when it is round off, it doesn't know it
> is 1.2345 any more.
> 

But you wouldn't complain about this would you?

>>> print "%10.4f" % 1.23445
    1.2345
>>> print "%10.3f" % 1.23445
     1.234

A value which is slightly than 1.2345 prints to 4 decimal places as 1.2345 
and to 3 decimal places as 1.234.

That's all that happens with your value as well: 1.2345 is not exactly 
representable as a floating point number, and the nearest representable 
number is less than 1.2345.