Support for decimals where your target might be Python older than 2.7

decimals.py

import sys
from decimal import *


LT_27 = True if sys.version_info < (2, 7) else False


def f2d(f):
    """
    Convert a floating point number to a Decimal with no loss of information
    from http://docs.python.org/release/2.6.7/library/decimal.html#decimal-faq
    """
    n, d = f.as_integer_ratio()
    numerator, denominator = Decimal(n), Decimal(d)
    ctx = Context(prec=60)
    result = ctx.divide(numerator, denominator)
    while ctx.flags[Inexact]:
        ctx.flags[Inexact] = False
        ctx.prec *= 2
        result = ctx.divide(numerator, denominator)
    return result


def d(f):
    return f2d(f) if LT_27 else f