[issue4796] Decimal to receive from_float method
report at bugs.python.org
Sat Jan 3 11:40:43 CET 2009
Mark Dickinson <dickinsm at gmail.com> added the comment:
Instead of the repeated divisions and Inexact tests, how about a direct
approach: n/2**k = (n*5**k)/10**k, so something like:
sign = 0 if copysign(1.0, self) == 1.0 else 1
n, d = abs(self).as_integer_ratio()
k = d.bit_length() - 1
return _dec_from_triple(sign, str(n*5**k), -k)
should work, and would likely be faster too.
I also think the sign of 0 should be preserved: i.e.,
Am still reviewing---more comments to come.
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