Stefan Krah added the comment:
I agree with Mark's arguments. Yesterday I tried to use as_decimal() in
a small program and it did not feel natural to me. I'll probably continue
to use Decimal(f.numerator) / f.denominator.
If this goes in, I'd prefer that as_decimal() always uses a localcontext().
As the patch stands, using as_decimal() pollutes the global context flags,
which can be quite unexpected:
>>> from fractions import Fraction as F
>>> F(1, 3).as_decimal()
Decimal('0.3333333333333333333333333333')
>>>
>>> import decimal
>>> decimal.getcontext()
Context(prec=28, rounding=ROUND_HALF_EVEN, Emin=-999999, Emax=999999,
capitals=1, clamp=0, flags=[Inexact, Rounded], traps=[InvalidOperation,
DivisionByZero, Overflow])
>>>
If the function takes a context argument, it might be better to move it
into the decimal module as Decimal.from_fraction(context).
So I'm -1/7 on as_decimal(), but +1 for the __format__() method.
----------
_______________________________________
Python tracker <rep...@bugs.python.org>
<http://bugs.python.org/issue15136>
_______________________________________
_______________________________________________
Python-bugs-list mailing list
Unsubscribe:
http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
