Function IEEEContext

Lib/_pydecimal.py:425–443

Return a context object initialized to the proper values for one of the IEEE interchange formats. The argument must be a multiple of 32 and less than IEEE_CONTEXT_MAX_BITS.

(bits, /)

def IEEEContext(bits, /):
    """
    Return a context object initialized to the proper values for one of the
    IEEE interchange formats.  The argument must be a multiple of 32 and less
    than IEEE_CONTEXT_MAX_BITS.
    """
    if bits <= 0 or bits > IEEE_CONTEXT_MAX_BITS or bits % 32:
        raise ValueError("argument must be a multiple of 32, "
                         f"with a maximum of {IEEE_CONTEXT_MAX_BITS}")

    ctx = Context()
    ctx.prec = 9 * (bits//32) - 2
    ctx.Emax = 3 * (1 << (bits//16 + 3))
    ctx.Emin = 1 - ctx.Emax
    ctx.rounding = ROUND_HALF_EVEN
    ctx.clamp = 1
    ctx.traps = dict.fromkeys(_signals, False)

    return ctx


##### Decimal class #######################################################