[issue4114] struct returns incorrect 4 byte float

[STINNER Victor]

STINNER Victor <victor.stinner at haypocalc.com> added the comment:

"Since 32 bit floats only have ~7 digits of precision, I expected to 
get the same thing back. Not 7 digits + garbage."

This problem is a well known problem of conversion from base 2 (IEEE 
float) to base 10 (Python unicode string). Search for any programming 
FAQ, eg.
http://www.python.org/doc/faq/general/#why-are-floating-point-calculations-so-inaccurate

"Python is just reflecting what C is doing": the problem is deeper in 
the silicium. If you want a better precision, use an arbitrary 
precision float type like decimal.Decimal() or the GMP library 
(Python: gmpy)

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue4114>
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