R. David Murray added the comment:
Please read about floating point arithmetic in the tutorial:
http://docs.python.org/tutorial/floatingpoint.html
Also observe that this works:
>>> Fraction(Decimal('1.23'))
Fraction(123, 100)
So yes, it is a limitation in how floating point is rep
New submission from bsidhom :
The Fractions.from_float() call returns an incorrect value when run on certain
numbers. Some test runs have been listed below. Note that this problem does not
exist when the same float is converted to a string and then passed to the
standard Fraction() constructor
